On can find on the website AlienBabelTech some photos of the future Radeon HD 5970.
This card features two GPU HD 5870, in other words a source of raw power but also a massive energy drainer (left photo). So far, Apple never supported dual GPU cards on Mac OS X. With Snow Leopard, and Open CL, things might quickly change as one GPU could be used for rendering:display, while the second one could be used for GPGPU tasks.
