<< We’ve asked our sources for screen shots of what Google Voice Desktop looks like. We didn’t get those, but we did get something better – the actual application. We’ve taken a video (above) showing what the application looks like, showing both outbound and inbound calls. This is mostly still branded Gizmo5, although the sign up screen says “Gizmo5 by Google,” and it is fully integrated with the Google Voice service, address book, etc. The Desktop application was also automatically added as one of my phones in the Google Voice for the browser. We don’t know if this is the current internal release or something more dated. >>

http://techcrunch.com/2010/07/01/exclusive-video-of-unreleased-google-voice-desktop-app/

Okay, why is there any question about releasing this app? Whether or not they release the program itself, it should take advantage of standards, jabber, sip, WHATEVER, so that i can connect using what client i already have.