Why 2D?
Like, an order of magnitude less money. That pretty 3D world and characters that you're covering up with raid huds? It ain't cheap. With 2D, we don't need dozens of artists to do models and skins and normal maps and rigging and animation. We don't need to spend millions licensing Unreal Engine 3.
Flexibility
Hmm, so what should we do now that we're not spending all our time and money trying to dig into the uncanny valley? ...Anything! Anything my artists can draw up I can put in the game. After all, it's just a sprite, maybe a collision shape, and some code. We'll be able to fix bugs and try out new ideas faster than anyone.
Twitch! But...easier
Ah, MMO combat. Push hotkey, make sandwich. Some players are yearning for action, instead of watching cooldown timers. They want in-game success to be determined by something other than ass-in-seat time. Others can't stand the idea of being 1-shotted by 12 year-olds with near-precognition reflexes. Navigating and shooting in a 3D world with a mouse and keyboard is just much harder than a 2D one--especially if you don't play FPSs. 2D levels the playing field. Combine that with well paced combat, and I think we'll have a system where you can show off your skills and your tactics.
Oh, yeah
It's way less laggy 
Play from your netbook!
What’s Asterax?
"Asterax" is the working title for an MMO project we're working on here at LiftOff Studios. It's not yet announced, so it doesn't exist.
Despite not existing, it's a 2D, top-down action shooter with a deep strategic endgame. We're stripping away the features that make traditional MMOs expensive behemoths, and focusing on making an instantly-accessible game in a world that players have an unprecedented amount of influence over.
Information will be leaked periodically here, as we move toward an official announcement.