I had a bit of time last night to look at the new mysteries book.
I read the introduction and lightly scanned the chapters on mystery mechanics and the chapter which provides the general toolbox full of virtues and flaws.
I read the chapters on alchemy and astrology. When reading the alchemy chapter I slipped to the back to study up on imortal magi becasue, like in fourth edition, the elixer is a product of alchemy that produces imortality. This morning I looked over the chapter on talismans.
The mystery inititation scripts are not as explicitly defined as we saw them in the mystery cults book because the complete rules for developing initiation scripts are up in chapter two (which I sort of scanned breifly before I dove into reading about goodies for the characters).
Alchemy has several virtues associated with it. There is vulgar alchemy that lets you add additional shape and material bonuses to items via the experimentation rules to pump up your lab score when enchanting an item. (vulgar alchemy and planitary magic are both minor virtues that give lab bonuses, a character with both could give a fair run to a verditius who hasn't learned too many of his house's inner mysteries)
Hermetic alchemy allows accelerated distilation of vim vis and slow distilation of other sorts of vis.
Philosophical alchemy (both major and minor versions of it) allows for vis distilation and for the opening of items for enchantment on auto pilot.
The Elixer has major and minor versions as well. The minor version allows a magus to supercharge a longevity ritual tha thtey create for themself. The major version grants imortality in a form that's not too different from a magical version of the merinita becomming mystery.
Going faster, Astronomy... + 5 to darn near anything magical that you want if you spend the time to do your homework first, myriads of charged items, astronomically influencing your enchanted devices, and the most flexible, utilitarian, powerful set of spell durations that we've seen to date.
Talismans... a minor virtue for attunement s galore and a major virtue for being able to set up muto vim powers in your talisman to target spells that you cast (this can be incredibly huge) with some other bonus rolled in that I don't recall because I didn't look up the reference.
The example mystery cults that I looked at seemed to have thematically strong collections for virtues and intiations. The cult in the astrology chapter initiates the astrology virtues, divination, and magical potencies associated with the character's birth sign and planet. The cult in the Alchemy chapter initiates the alchemy virtues, planetary magic, and something else that I've forgotten.
Just listing the goodies doesn't really do the book justice though, don't be scared off just because I'm excited about min-maxing.