Android 3.0 Honeycomb is the tablet-optimized version of Google’s mobile operating system. Check it out here, outside of the tablet environment. Specifically on an HTC Desire HD phone. Most phones have too small of a screen to make Honeycomb usable, but that might not be the case with the Desire HD, which has a 4.3″ display.
Performance is fine. Could be better, but with the larger display, using Honeycomb on a phone becomes a lot more manageable. Performance won’t be the best of course, but at least they proved a point.