Google just announced during the keynote presentation that Honeycomb is officially being updated to Android 3.1. The update will begin rolling out today for owners of the Verizon Motorola XOOM 3G - no word yet on when the WiFi model and other 3.0-rockin' tablets will receive the update, though.
They mentioned a few key improvements they've made with 3.1, though we're sure they only just scratched the surface. For example, they've improved multitasking to now allow more apps to run simultaneously. To make sure the performance doesn't suffer, though, they have a system in place that automatically halts and shuts down apps as available (presumably without making any sacrifices in terms of usability). Widgets can also now be resized as needed, much like in Launcher Pro Plus. They've also expanded support for peripherals with USB host support, though apparently that still needs some work - they unsuccessfully attempted to demo a game being played with an XBOX 360 controller.
We're sure more details are forthcoming - stay tuned and we'll let you know as we learn more.