iCloud where's it all at as far as Apple's concerned. Expect to see more integration, especially in light of OS X Mountain Lion, due at the end of Summer. This might be as simple as inviting developers to make better use of iCloud to store their own data.
Maybe some kind of doc sharing service in iCloud? Perhaps even user-generated content sharing too -- if you record a movie, you'll be able to share it with anybody easily. Video sharing is one area underserved at the moment and much talked-about by tech journalists.
Maps will be improved, probably. Expect elementary turn-by-turn navigation using Apple's own map data. I'll bet money this will only be available in Europe and USA for at least the first few months, however. Apple might offer more functions for a premium, such as spoken directions.
There might be more geofencing stuff too. I'd like to be able to switch settings if I leave a particular area, for example (like turning on 3/4G when I leave the house).
More Apple TV integration, most likely, especially if Apple's really going to launch a TV soon. Expect things like TV remote control apps and perhaps a listings app too, but only if you have a corresponding Apple TV. But do expect to use your Ipad or iPhone has a controller for your Apple TV.
We might finally get Facebook integration, on a par with the Twitter integration.