Larrabee as a GPU is a trojan horse.
With 32x 512-bit vector MIMD it will whoopass CUDA.
512-bit can handle 8 double precision (32 bit) or long integer variables. And 32x. That is equivalent to 256x the speed of a regular math unit in a single core processor.
That means for math work, Larrabee has the potential to be (256/4)=64x as fast as a quad core CPU clock-for-clock. It will probably be running at half the frequency of a regular CPU, maybe slower. But that will equate to at least 16-24x the speed of a quad core.
And math libraries can be very rapidly modified for Larrabee x86.
nV know this. GT300 has to compete. Look at the panic in their eyes.
Moore's Law will be bust open for the 2008-2010 season. And the Soda-Darwin law applies: survival of the fastest.