Google just announced the Android 3.0 Honeycomb platform highlights which include tons of new features such as a new "holographic" UI theme, an interaction model that builds on multitasking, notifications, widgets, and many others.
There's a lot going on under-the-hood too: Android 3.0 will get support for multicore processor architectures,new UI framework for creating tablet applications as well as high-performance 2D and 3D graphics:
A built-in GL renderer lets developers request hardware-acceleration of common 2D rendering operations in their apps, across the entire app or only in specific activities or views. For adding rich 3D scenes, developers take advantage of a new 3D graphics engine called Renderscript.
More screenshots and video
(Copy/paste selection, keyboard)
(Android 3.0 camera)
(Android 3.0 browser)
And here's a video with Android 3.0 Honeycomb "built entirely for tablet" in action:
Check out the full announcement @ android-developers.