I love the use of the "desktop-level graphics" as if DirectX support is all that's needed to equal what you can get on good gaming PCs. Glad to know that the graphics in a netbook's AMD C-30 (a Radeon 6250) are "desktop-level" every bit as much as that 6990!
The problem here, though, is I've had a hard time figuring out just what a "core" is... I do know that PowerVR's MP series uses multiple "cores" that is slightly wasteful given the redundant silicon vs. a single-core, multi-SP chip. (it's a tradeoff in exchange for easier scalability) If the above diagram is any indicator, then perhaps each "Core" consists of 4 shader units, which means an 8-core GPU has 32 stream processors... Not exactly impressive compared to a PC, or even really a netbook, but should be fine for a phone, since that puts it on a par with a PSV or 3DS. (this 4-per-core matches with the figures suggested for this chip's predecessor, which tops out at 4 cores)
Of course, a bigger question will be its memory bandwidth; that's a spot Sony's and Nintendo's handhelds thrash phones, which have to rely on much-slower RAM to focus on conserving power when NOT gaming.