We got our first look at Google Music Beta at Google IO this year, and it looks like some who requested invites are finally starting to see a response. Your Google Music Beta invite nets you just one invite (none to give out) that works across all your 2.2+ devices.
Uploading is done through the browser-based web app and music syncs in the background. Expect more as we find out.
And anyone who gets an invite, let us know how it's working for you. Sound off, comments, you know the drill.