Aros is for people who want the power of the PC, but don't want to run Windows, Linux or OSX to harness it.
Until AROS gets working 64-bit SMP and OpenCL (on the reasonable assumption that CUDA is a complete impossibility), I'll still have to stick with Linux to harness the power in mine.
Mind you, the only times I ran AROS on it recently were via linux anyway, so actually, that's not really much of a problem.