Yeah, I think this is more likely too.
Speaking of which,
Is Heirs to Merlin available as a .pdf anywhere (legally I mean)? Because I can't find it?
I believe that if it isn't on e23 (and it isn't), then it doesn't exist. Which is a real shame - I'm frankly tired of lugging around multiple books. I want my supplements in digital format, please.
Try Amazon. They seem to have 4 of it(1 new 3 used).
There are, but for £30 or more ($45) +p&p, which seems a little steep...
I guess I'll just have to keep an eye on ebay (they occasionally pop up at more reasonably prices),
Annoying when many of the newer (and older) books are available on pdf,
If ArM6 was released, In would simply like my players to smirk at supplements as "EXCEL books" instad of sources of background information. Some stuyff like Hedge Magic needs extra rules, but there are too many tangential stuff scattered through all the supplements in our opinion. Simplifying and getting most rules together would be useful.
As said in another thread by someone else, an expansion in setting information in the core book would be highly appreciated as well. ArM3 and ArM4 were better in that sense. I love the current setting chapters in the current book, since you can build a whole saga out of them (and that is ubber cool) but the background information on the game world is quite lacking, specially on the OoH (houses, tribunals, traditions, Covenant living and the Code).
Xavi
IMHO, ArM6 should be drastically simplified, rule-wise.
Thanks David - that is a bit more realistic,
Then where would I go for my 'RPG that has enough bts and corners that it's actually fun to fiddle with for the rules alone'? 
GURPS just simplified as well recently
Why a 6th edition ?
Currently, I have the feeling that all the core books from previous editions are at least done for 5th edition. I would love to see more content now.
No crunch: adventures, plot ideas, more background. Currently for example, the various secret societies are described only stat-wise.
A section in a book exploring this aspect of arcane society could be interesting. We do have partial descriptions on most of them, nothing more than stats, it leaves a lot of work on th hands of overworked SGs...
Or more stories involving faeries. The interesting thing with faeries feeding on stories is that it could allow any kind of stories to be dropped on the head of any player, etc etc etc.
I don't think we need more crunch, we could use more fluff as fluff is always funnier than crunch... Personnaly, I have a day job, so any book that gives me ideas / plots / NPCs to steal is a lifesaver as it would allow me to save time to prepare my games...
Even if it ends up as being a pay to download format, I would be willing to cough up a few dollars on a 30-60 pages PDF containing info a specific secret society, with some NPCs, backgrounds, locations, NPCs, motivations, etc etc etc. Does not need to have high-end illustrations neither.
I love to run games once every other week, every week if my players are available, but that requires a lot of source material to keep up the ispiration 
Just a thought,
François
I was trying to read all the posts, then i gave up.
5th is pretty good already imo, and lets be honest, the opinion of everyone on these forums, else they wouldn't be here, or playing.
things i'd change
Wards. not the magic resistance, i like that (big bad guy shouldn't be stopped with a simple generic spell). More how it sometimes stops completely, other times gives a soak bonus. Needs more unity.
Tremere. poor house virtue, and have to jump when told to. Wouldn't play one (i'm a munchkin at heart).
Multiple casting - a casting penalty when used (i HR a penalty of total additional magnitudes).
Dual wield (maybe not historically accurate, but fun).
More examples of mechanics in play. Examples of combat, spellcasting, typical vis sources, book levels. It would however make the book much thicker, more expensive. Maybe 5th edition, Deluxe.
My vote goes to 'no 6th edition for a long time'.
There are a handful of issues with the 5th ed rules, as mentioned in various posts. Otherwise, the only real problems people are talking about involve finding particular rules and how they'd like them in a logical location/order/summary.
I'd like to see a 'revised guidance on wards and other problems'.
There are currently lists of where each virtue/flaw, each ability, each spell guideline is, on the Atlas website (thanks guys!).
That would do me nicely. I don't want to have to buy more books - I haven't finished getting even half of the current ones! I don't want to have another set of obsolete rules cluttering my mind/game. I don't want to have to re-boot my saga. I currently have too many 4th ed rules still in use to appease players who didn't want to switch to 5th ed in the first place!
If a 6th edition came out, many players would still be playing 5th ed for many years to come. It's only the rulebooks on aspects that 4th ed never touched (eg RoP:Magic) that made some of us switch to 5th. Each change reduces the population playing it, unless it recruits people who never played the earlier editions. I started playing Ars Magica when the free 4th ed rule book became available online, but I suspect that most players of 5th also played 4th or earlier. How many still play the previous editions?
A new version would need to be so different, and marketed really well, that completely new people want to play it. And that will lose many of the existing fans.
Gilarius
I don't want a 6th edition of Ars Magica particularly as I am happy with 5th. If it was simplified I would not buy it , Ars Magica's magic system to a large degree defines the game for me . Simplify the rules and I see no need to have them.
I did not talk about the magic system, though it could definitely be simplified to some extend while retaining the Tech+Form priciple. That's the very core I love. But many things have become cumbersome (notably V&Fs, experience + what requires too much bookeeping). ArM used to be an innovative RPG. Now it fits the retroclone fashion pretty well. 
Keep yer hands of experience
Seriously though - the experience system could do with some work, but having XP assigned to abilities (and the XP system as a whole) makes Ars distinctive, and really shapes the game (makes it more about a campaign rather than a couple of adventures),
V&F though could do with some serious work, and there are so many unique formulae popping up all over the place and extra guidelines, etc (spell guidelines are a pain because there is nowhere that they are all simply summarised).
I guess in terms of complexity what I am saying is that the materiel in the core rulebook is fine as written (aside from the gripes noted above), however, the supplements introduce too many unique elements that should be distilled down to a bare minimum (fewer P&F (which I generally find badly written BTW, as they often miss out elements like prerequisites), and magic systems that should mirror hermetic magic with flavourful twists rather than adding loads of random other stuff (I like the Methods + Powers style, and it mirrors Tech + Form neatly - why not take it the rest of the way and just consider them to be "Arts"))
I still think the core rules could be streamlined, but I even more strongly agree that sourcebooks indeed bring more complexity that should be reasonable.
I would not enjoy that at all.
I fully agree with Marko. There are too many RPG's around with lite to none existant game systems or fat too generic. Ars 5 has a system which creates a game world, too much simplification and you lose everything.
That's true for the magic system (although adding less different numbers in casting total might be nice), not so for the abilities system which is classic characteristic/attribute + ability/skill + die vs difficulty level. Of course some abilities are quite specific (artes liberales for instance) but the mechanical system is not. I would be quite happy if a different, more context-specific, system would exist.