Q&AInstantAction is opening up their service to other games, and they say "porting" is simple (1-2 hours) for devs. So you can run any game in your browser.
Well, not totally true. The browser is just a front end that downloads the game and can display it in a window. The game is actually running from its own executable on your local machine. Quake Live works the same way. The question at the end of "Can you play Gears of War in the iphone/PSP browser?" is silly, but I can see people getting confused.
Anyway, kind of cool. I wonder where this kind of thing will lead us. Flash games are fun but limited. Allowing more "full" games to be played simply by visiting a web site is a cool idea. The problem I can see is people used to Flash games not understanding why Gears of War doesn't run well for them...I mean, its a "browser game".
*note: Gears of War is just used as an example and is not on InstantAction.