I see a lot of posts on here about not liking Sony's version of Android. After watching the videos and talking to the reps I can say with certainty:
All they did to android was change the bar blue and put a gradient on it.
The floating boxes and graphical stuff everyone goes crazy about isn't android or a custom UI. It's just apps. They seem to have replaced the default Gallery/Pictures app with MediaScape and the default address book with TimeScape. That's all that they've really confirmed doing. Perhaps a few little gradient effects here and there, but all in all it's pretty much standard with extra shortcuts and apps in it.
There seems to be a lot of hate about their apps and people thinking that the TimeScape addressbook thing is the homescreen. You can set it to the homescreen, but the default is the standard android homescreen.