I think the really big thing that is going to change tomorrow is the distribution system for ebooks. Details are sparse, but they appear ready to go forward with what is being called the "agency model". Right now it just sounds like a marketing scheme. We'll know more when they announce it tomorrow.
What I'd like to see is something similar to a subscription service where you could pay a monthly fee and read any book in the catalog, but when your month runs out they all become inaccessible. But that's just my imagination. If they did that, I'd be the newest fan of Sonya Gomez!
The problem is that the DRM has been stripped or will be stripped. ePub & Mobipocket already have time limiting DRM but both can be streipped and there goes the time limits.