I'm confident that notifications are going to be a part of it, but when they plan on dedicating the whole keynote to software releases, one wonders how they can sell it.
iCloud, iOS 5 - maybe some great stuff for developers such as Apple-hosted databases. Personally, I am crossing my fingers for an iBooks overhaul, but that's probably too optimistic.
Buy a book on the App Store and you're confined to ONLY iOS devices.
The book selection is also very meagre[3] (at least in this country), but more important, some of the available free books are typeset from hell. It's just a copy-paste of Project Gutenberg and similar endeavours, which are not formatted for iBooks at all. This does not inspire me to buy any iBooks, and it leaves me to wonder how the (free) book user experience can be so bad, when Apple make such an effort of vetting apps from trivial ailments.
Another, perhaps minor, thing is that I can't highlight across pages, which drives me absolutely bonkers.
If I were an author (or worked for one) and wanted to release a book on iOS, would I distribute it via iBooks or create a native app for it like Al Gore did? I honestly don't know, and I have a feeling that my hesitation has more to do with the shortcomings of iBooks than the allure of making a standalone app.
[1]: https://kindle.amazon.com/profile/Craig-Mod/52461
[2]: I'm sure it would be in Steve Jobs's best interest to make us forget Ping as soon as possible. Better to replace something vapid with something slightly high-brow.
[3]: It doesn't even have A Song of Ice and Fire!