There is 9 minutes left until the Keynote at WWDC starts so i'll take this time to give out my guesses.
1. As everyone is suspecting, a new interface for iOS. I am going to guess that the icons are going to be similar to that of the WWDC and the interface across all apps will be close to that app.
2. In text/email functionality. Something I haven't seen much talk about but I believe Apple needs to add is in app texting and emailing functionality. As you have seen you can tweet from any app, via the drop down menu. Why can't I text or email from any app? It's annoying to be watching hulu or youtube from a device get a text and quit the app, stop listening, text and go back. Doesn't Android do this already?
3. Obviously it wouldn't be a keynote unless a new product is shown. I know this whole talk on iWatch has been on the horizon. Even Cook said he was interested in on body technology at D11, so I don't want to guess iWatch as a stand alone product but maybe something that integrates with your already on you iDevice.
4. Tuned-In - this is something only I think have thought about. Apple has been on the hunt for iRadio type product. Recently, Tuned-in updated it's interface and it's pretty flat. It's black and dark and the interface has been cleaned up pretty well (though I still think there is room for improvements). I'd love to see Apple teaming up with Tuned-in or even buying out Tuned-In for their future Radio product. Considering Tuned-ins' fan base, it wouldn't be a bad move.
That's all I can think of and there is one minute left! LET GET GOING! WOOT!