This is amazing. Every time there's a discussion like this someone comes up and says 'there wouldn't be space for it'.
We heard the same thing when it was rumored the spring 2009 mini would have 5 usb ports AND a firewire port - 'there wouldn't be space for it in the case'.
We heard the same thing when it was rumored that the aluminum Macbook would get a firewire port - 'there wouldn't be space for it in the case'.
A few people like you, would show pics of the inside of the case to 'prove' their point.
Well guess what, Apple can redesign the insides, move things around, make a few things smaller - and MAKE space. They've done it before. Besides, even if there wasn't space, they could knock out one of the usb ports to create that space (isn't 4 usb ports enough for most of us anyway?).
So please, my friends, let's give this 'there wouldn't be enough space' b-s a burial once and for all.
It may not be a question of space, but one of heat. GPUs tend to run hot.