How about quad GPUs in a console?
http://i.imgur.com/LMI2y.jpg[IMG]
Seriously though, a Multi GPU setup in a closed box actually makes more sense than a multi GPU setup in an open box. On you're PC, the task load in a dual GPU setup is divided up in a generic, one size fits all manner. One GPU fills in half the screen and the other GPU fills in the other half. This way the algorithm will work with any pair of identical GPUs and will evenly distribute the load over both so one GPU doesn't hinder the other. In a closed box, the developers will know exactly how much power each GPU will have so instead of dividing the load by screen space, they can divide the load by task thus utilising both GPUs more efficiently.[/QUOTE]
Yeah... ummm...
There's a slight difference between what is in the Vita, and what some are proposing in here.
For one those GPU's in the Vita barely use any heat or power. While a couple of GTX580's would set your house on fire... if confined in a case as "small" as a PS3.