I just updated the device. Didn't notice any changes in the interface for now. We'll keep track of any changes found here.
Many say v1.2 is faster than v1.1 . I also think this is true, but it could be because of our joy for the new firmware ;)

[Thanks for the tip djmetsandy ]

EDIT1: Software Update v1.2 with bugfixes and Vista compatibility is also released:
http://www.zune-online.com/news/zune/zune-software-update-v1.2.html

EDIT2: To semi-manually download the Firmware update go to the Sync menu in the Zune Software select sync options -> your_device_name -> Check for Zune Device Updates