I think you forgot to mention one extremely important factor.

Everything on Gaikai systems is rendered in the cloud and you just need a device with a web browser capable of running flash.

That really opens the doors as to what devices you could run these MMO's on.

This shouldn't have problems running on any netbook so you could be running WoW on very low power weak devices without a problem as long as you have a fairly decent 1 to 2 megabit connection at your disposal.

What I'm really interested in is how well it all scales though.

Since they are running multiple copies on servers surely a faster connection means higher resolutions and more eye candy while less bandwidth means lower resolution and less eye candy.

Either way it all seems very ambitious with the way they are approaching it as opposed to OnLives more radical approach so we will have to see I guess.