It's been a ton of fun and I've learned a lot of things along the way, but the time has come for me to step down from GV. The latest Google Voice update adds the ability to use other Google (not just GMail) accounts, which was the missing "killer feature". As such, I don't see much reason to keep maintaining my GV application. I don't have the time any more to re-implement their API, and I feel that users would be better served by the official application.
Later today or early this week I'll be pushing one final update to GV which includes a patch by Mark Guppy. If anyone else wants functionality added to this app, feel free to write a patch and email it to me. If the installed user base falls sufficiently low, I'll pull it from Market (though updates can always be found here: GV Downloads.
On to happier topics: I've released an app that I've been working on for a while now: Magnatune - an app that lets you browse the entire Magnatune.com collection from your phone. There is also a RESTful API (which the client is based on) that I will be exposing later, in case you want to write an app for another platform (or even Android). Please drop me a line if you have any feedback; I'd love to hear it!