Google Voice is still great for having a spam-box phone number you can give to places that require a working phone number (car dealers, political organizations, etc.), but you don't really want to hear from. But if that's how it ends up being used, I don't think that's going to convince Google to keep it around. You can tell it's been unloved for some time now... The iPhone app (at least) was updated once all of last year, and the only thing in the update was a warning if you try to txt 911. (So it was probably prompted by a legal issue.)
Maybe now that Google has a mobile phone OS and has to work with all the mobile carriers, there's outside pressure to hold Google Voice back. Well if it goes, so much for my spam-box.