That's right, Google Voice is finally available to anyone who wants it. No more begging for invites! (So please. People. No begging for invites.)
We'll see what happens from this point on... whether or not Google will start charging for it... but the one thing we know for sure is that they're hard at work on Gizmo5 integration. It's likely we'll see a desktop client (probably Windows-only, but I do hope there's a Linux version) and a web-based client in Gmail.
To all the new users... I think you'll love Google Voice, especially if you're already an Android user. There's an app in the Market, so if you are an Android user, make sure you check it out.