BLink- a short ranged teleportation
Windgust- a storm of wind
Possession- embody the souls of others
Stop time- stops time

Any others we know of?

I'm pretty sure summoning rats was discussed.

It seems interesting.

Bah! i fail to see how summoning rats and possessing them will add to my experience, however...
1. you dont know until you try/know how it works
2. its innovative
3. as long as the game is filled with awesome content and freedom i can play the game without even possessing a rat once. but i will though, i will try everything the game has to offer.
gameplay freedom and depth FTW.

and there is the fact that the devs said if you can possess humans and other animals it would not make sense if you couldn't possess rats. forgive my ignorance.

I'm not sure summoning rats is in there. From what I can tell, the rat-related gameplay has always referred to rats you might encounter along the way. I don't think it was even alluded to. It's been a few months since I've read any of the articles, though, so I might be wrong...

Never mind, rat-summoning is in there. http://www.rockpapershotgun.com/2011/07/11/dishonored-preview/#more-65898, there is magical healing.