I found it for download in the store today. I played a little bit and it was quite a bit of fun, but definitely a beta! There are some issues with the voice chat... lots of background static in some servers, voice chat suddenly disappears at times, and you sometimes get feedback/echo and can hear your own voice a couple seconds later.
The most annoying thing was how often I got dropped. I'd say that 9/10 games I joined I would get disconnected from within 5 minutes. I double checked all my network settings thinking maybe I have an issue on my end, but everything was working fine (NAT still type '2'... which is what you want to see if you are behind a router). So I checked the beta forums and apparently it's a common problem... oh well.
So I really enjoyed the game when I was actually able to play for more than a couple of minutes, but lots of problems to deal with too. This was the first day of the beta though and this is what betas are for.