:( According to Apple, OSX compatible graphics card on Lion are:
OpenCL:
GeForce 320M, GeForce GT 330M, GeForce 9400M, GeForce 9600M GT, GeForce 8600M GT, GeForce GT 120, GeForce GT 130, GeForce GTX 285, GeForce 8800 GT, GeForce 8800 GS, Quadro FX 4800 o Quadro FX5600 de NVIDIA.
Radeon HD...