StarCraft Universe PvP is playable as of today via Battle.net, but you'd better hurry because the fun only lasts through October 30th. At that point, the game will be taken down "for further polishing since technically it isn't even ready for an open beta."
The playable portion features an arena called the Encephalon Grid, and testers will start at level 30 (fully geared). Every class is available, and players may also be able to unlock additional abilities by winning enough matches. Check out the full press blurb on the mod's official website, and get a load of the PvP video after the cut.