Where is the preview of Dies Irae?
Don't think there is one. It would give too much away.
Why buy it?
Because it's the last book of this edition. Because the sagas outlined within are epic. Because the authors shed blood, sweat, and tears. Because there are things there that transfer to sagas that don't bring about the end of the world.
Still can't purchase it in Italy... 
Come on, take my money!
It's true that the ToC would likely give a lot away, but Atlas has given us glimpses of the Introduction in previous adventure books like Thrice-Told Tales and Tales of Power so that's an option. In any case, still waiting on my own copies... 
If anyone would like to be so kind to PM me the plots in this book, i would appriciate it as I will not buy this book without knowing whats in it
My copies finally got here. Too bad costums got hold of them for a bit.
EDIT: I'll run the risk of being accused of puns:
Opinion: Jättebra.
End of the World Plot 2, The Enigma Variations:
Criamon magi figure out how to shatter the prison of time, freeing Criamon the Founder to walk the world once again. Unfortunately, this also releases Nomairc the Unfounder from the Counter-Alam, who has been waiting for his disciples to shatter the prison of time and return the world to the primordial age of perfect disharmony. Now Mythic Europe is the stage for a titanic death match between Criamon and Nomairc for the fate of all the worlds. Regardless of how it ends, or if it ends, nothing will ever be the same again....
Maybe I will buy this book, but I seriously doubt it. It does not sound as my cup of tea so to say. With only one of the four stories sounding intresting, I believe that I rather spend money on something else. Though I ope that all other people liked it better, but to me it sounds a bit of a disappointment.
Chapter Sections in my own words.
The End of Time - House Criamon seek to destroy the world by bringing about the end of time by bringing down the moon.
Fimbulwinter - The Norse try and destroy the world by bringing about an eternal winter.
Great Pestilence - A Hermetic magus accidentally destroys the world by creating a great plague that eats the Arts which has ramifications on the world itself.
The Twilight of the Gods - Loki seeks to free the Titans and thus release magic and thus destroy the world as it is known.
++
Honestly, there are elements of all four categories that are interesting and cool but all in all its not exactly the most amazing work of Ars Magica.
Aetherial Magic in the End of Time is nifty. I like what it represents and I like how it breaks the lesser limit, especially as I like when the lesser limits are broken. I have some nifty ideas on how to use Aether magic cause it totlaly has enough explanation that it could be brought into a normal campaign.
In the second story I also like how the Order will survive if winter comes upon them, it has some nifty spells and stuff. The potential of such hostile survival encounters is pretty nifty and cool. It has a lot potential for cool adventure.
The Great Pestilence is interesting. I like the write up of how the plague deals with the arts, so that is cool and iit provides a lot of information. I am not sure if I would use it but I know there is totally some cool info here that can be used. Plus its totally a saga worthy of a post-apocalyptic campaign and I like the potential of what happens to those who walk back out after the plague passes through. Its a mighty changed world.
The Twilight of the Gods has some cool elements of what happens when magic is not as restricted and becomes a bit more dominant, which is cool. I HATE the breaking of bonds, which destroys the familiar and causes aegis of the harerth to fail automatically. I LOVE the nature of what happens to faeries, its a perfect way to transition the Faeries into House Elves, so its got my vote. The fact that the Gifted need to serve daemons to use their magic annoys me, the gift is part of the soul and should automatically give one access to magic, which is how I would do that.
I recommend it for those who are completion and those who want saga ideas and stuff, but honestly, its interesting but not spectacular. Though I will say the writing is great, its a top notch piece of work, even if some of that themes aren't super what I wanted. I understand why the last book was a book about end of campaign scenarios, but I wish they had something a bit more game changing than simply end of the world scenarios. But its nifty and its on my shelf and I am reading through it with enjoyment, which is what I always hope to do.
The End of Time sounds pretty cool, but I'm really disappointed that the book of world ending scenarios doesn't seem to include the actual mythological end-of-the-world scenarios from what I'm understanding of what's been talked about on this thread. Like, I'm a lot more interested in seeing how to deal with Ragnarok, or the Apocalypse of Revelation, with more attachment to the European lore and more of an emphasis on how Order of Hermes interference in these events might break the setting. Unless that's covered in a second half of the book or something? If there's more info than I see here, I haven't found it, so I'm assuming that stuff isn't dealt with.
I wasn't on this book, but I can see why you'd not want to do Revelation. Basically God destroys the world in stages, and grabs all the unrepentant sinners and puts them in Hell. Including all of the gays. And the Jews. And the women who are a bit uppity. And the slaves who prefer to be free. They all get tortured in a lake of fire.
Because medieval Christianity? it's not pleasant at all.
I can see why you'd not want to close out on Mythic Europe by burning all of the minorities while the Good stand around hossanaing.
It woud have been exciting with a civil war in Order of Hermes when House Diedne returns.
Okay, but that's happening to all of the people in those situations who die anyway from what I understand, so, y'know, don't go into so much detail on that part and focus on the "destroying the world in stages" bit, and perhaps how magi can break the system and what happens if they do it partway. The mythology suggests that there's nothing anyone can do, but Hermetic magi break the proper mythological order of events constantly. This is just on a bigger scale, but that's to be expected in a book about ways the world could end.
I will admit that one of the things I do particularly like of the book is that there are always sections on suggestions of how players could defeat the bad guy and save the world, either wholly or partially. And there are ideas of how it can continue even with the world changed from what it was. Heck, two of the stories even have a section on how one could lead to the other (the winter one and then the magic one). My 'issue' is that I am pretty sure I wouldn't use them to destroy the world, but I do like the concept of how such massive changes could come to a game and still make the rules viable, which is interesting. Like the presence of the Art of Aether, that is a pretty interesting new field and has the potential to lead a campaign to become world hopping.
I am glad that the disasters are 'made up ones' rather than the actual apocalypse of the Bible - none of them are the Divine acts or even the Infernal gains power, and I am incredibly glad because of that. They are all Magical disasters, which is fitting for a game where Magic is the realm that is the most important in terms of player connection.
Well, David did say that the biblical Dies Irae wouldn't work for this project because... well, there's nothing magi or anyone else can do to stop or even survive it. Ergo the need for other, less lethal, apocalypse scenarios
+1. This is the most fitting way to end the gameline, for me - with huge MAGIC plots.
I don't accept that Revelations couldn't be done in a way that's fun and engaging, and where the PCs CAN actually save the world; one can always find a way. But I'm not at all too sad it hasn't worked out.
I don't really think I'll like most of these megaplots, but some yes (definitely the Ragnarork/Titans one, and perhaps the winter one - although a Faerie Russian Ice Queen seems far more fitting here). And that's enough. When this think comes out as PDF, I'm pretty sure I'll buy it. It definitely looks like a great way to end the line.
Starting to read through Dies Irae now.
First thought: does aether explain how species can move through invisible objects? It's invisible and (sometimes) intangible, but emits light, so could it be constantly emitting light within the object which is just sufficient to pass on the species?
EDIT: Second thought: but if there was enough aether emitting enough light for that to work, darkness wouldn't be a thing.