I like how apps are intertwined into each other. Example: the native music app links to other music apps on the phone (Pandora, Last.fm, etc.), in case you don’t want to listen to any of your music on the phone.

I’m not sure if I agree with integrating Facebook and Twitter into the Contacts app, since those platforms themselves change so much, it’s usually a better experience to use the associated app itself to get the "authentic" experience. Combining weather with a contact’s location is cool, and is just the beginning of how the interface ca provide more contextual awareness.