Google had 2 teams working on Gingerbread and Honeycomb versions of Android, and I think the big changes will come with Honeycomb, both UI wise and feature wise. I actually think they may be holding off some features from Gingerbread, just to make Honeycomb look like a much bigger release.
Andy Rubin was at the D: Dive into Mobile conference yesterday and as a surprise, he showed what looks to be a 10" tablet with a 16:10 resolution ratio ( I think 1280x800 just like the upcoming Acer tablets), which was apparently sporting the upcoming version of Android - Honeycomb.
Andy Rubin said the new UI will be more desktop-like, and you'll be able to "fragment" apps (yes, more fragmentation!), and turn them into widgets. They seem to be taking an approach that will better take advantage of the extra screen you have with a tablet, compared to a phone.
The tablet will also have a Tegra 2 chip, capable of 3D graphics, which should be more than good enough allow for hardware acceleration not only for the UI, but hopefully for a lot more, like the mobile browser.
Video-chat will also be coming to Honeycomb, which hopefully will help make "true Internet calls". Not that the SIP calls aren't Internet calls, but I find it disappointing that you will need a SIP account to make a phone call that uses the data plan instead of the Voice plan.
Via - Techcrunch