Update 9/2/11: Aaand now with the latest 0.4.2.36 update, Honeycomb support is official.
A short while ago, the Google Voice app received an update that brought about a few bug fixes. Almost immediately we began hearing rumors that a Honeycomb interface may have been incorporated into this build. A quick search of the Market revealed that it's not officially supported just yet, so I pulled the apk from my phone and sideloaded it onto my Tab 10.1. Here is the result:
As you can see, the settings menu moved from its previous location in the navbar to the upper right-hand corner -- the typical place for the settings menu of Honeycomb-optimized apps. While the interface is still very much phone-esque, this is a good sign that Voice will soon be officially supported on tablets.
If you don't want to wait for that day, though, go ahead and grab the apk from our mirror right here. Enjoy.