Google says that they're working on a dedicated Google Voice app for Honeycomb
Granted that some are dealing with the issue by simply accessing their account through the web browser, it’s still missing some inviting features that make a dedicated Google Voice app so crucial. Luckily though, it appears that Google is hearing the numerous questions and pleas regarding an app for Honeycomb. And with that in mind, they’re already hard at work in developing one for the tablet optimized platform.
Still, it’s rather difficult to concretely say when we’ll see an app become available, but it’s nevertheless pleasant to know that it’s on Google’s to-do list. In the meantime though, Motorola XOOM owners will have to make do with the web based experience.
source: Google via IntoMobile