I'm in there as Datasquid.
The client version is for Mac only currently. They are working on the windows client.
In the meantime the game is also available via web-browser at uberstrike.com or through a typical game plugin at Facebook (search for Uberstrike.)
I like it because it's as easy to hop in for a quick game before work, as it is to spend several hours with at night. The thing they're doing with the bluebox maps is pretty cool too. The map selection is about to explode.