New Devices:
There will be three new devices revealed by Google,
The new Nexus phone by LG - Nexus 4
A 3G version of the Nexus 7
A 10 inch Tablet by Samsung - Nexus 10 (with a very high resolution)
New Android Features:
Huge improvements to Google Now, cards will be different, a card comparing how much you've walked across months and a card that pops up when ever you go to a new city, showing all the POI's and distance to them
Changes to the Camera interface
Notifications get further improvements, now you can read entire messages in the notification center
UI improvements for bigger tablets.
And the keyboard will come with something similar to swype
[UPDATE] Profiles feature is coming for the tablets, not sure about the Phone
There can be more features that may turn up, these are the ones I'm 100% sure of.