I'm pretty excited about this for a couple of reasons.
I switched to Android recently, and have been having a blast with the Galaxy Note 2 with a Gameklip (
http://buy.thegameklip.com/) and PS3 controller. I was surprised by how many good games there are on Android, and by how many decent games all of the sudden become very good games when you have physical controls.
When I come home from work, I'd much rather flop on the couch than sit in front of my computer playing games. I also don't want to occupy the tv with playing games, since my wife couldn't use it then. It would be awesome to be able to relax and play PC games streamed from my desktop while laying/sitting on the couch.
I only really play handhelds at home on the couch anyway... Who cares that it's not pocketable? They are obviously catering to a different market/use scenario than the 3DS or iPod Touch or whatever.
I doubt my Pandora or Vita would fit in many of my pockets, but I haven't even tried as I only really pick them up to use them at home anyway.
Anyway, I'm pretty excited about this. If it's under $300, I'll get one.