Since we don't have the code base of TG 2 (almost) no one can know if it can be ported to CUDA / OpenCL.
However, the availability of GPU doing double precision FP means a lot.
Refer to this page ---
http://en.wikipedia.org/wiki/AMD_FireStream#AMD_stream_processing_lineupTake, for instant, the ATI 9270 (or HD 4870).
It has 800 stream cores, and it can do a maximum of 16,384 threads, all in parallel. Clocking at 750 MHz.
Compare this to the best Intel (desktop) CPUs of today. The i7 - 960, with 4 cores. Clocking at 3.46 GHz.
Do the math and you would come to the realization that, for real BANG for your bucks, GPUs really outshine CPUs.
Even if we half the performance of GPUs for performing double precision FP, and half the perfomance of GPUs
again,
just for fun, the net result is still mind boggling ---- The HD4870 is still capable of rendering pictures using double precision FP 10X the speed of the i7 - 960 !