Austin Robinson of NVIDA makes an excellent point during his introduction of a new CUDA-based ray casting engine (NVIRT) at I3D'09 [paraphrased from his slides]:
Rasterization is fast, but needs cleverness to produce complex visual effects.
Ray tracing robustly supports complex visual effects, but needs cleverness to be fast.
This is especially interesting because it was just a year ago NVIDIA's chief scientist was condemning ray tracing as a waste of time. Considering Moore's law with Robinson's observation, I don't really think rasterization has the lifespan most people are willing to give it. Remember wireframe, anyone?