Modern day high-performance consoles are very interesting beasts.
Some of them have powerful GPUs, with very clever architectures oriented for high-performance games, while others have killer CPUs that, in order to produce the same results as other consoles, you have to offload some of the graphics processing into the CPU, which basically contradicts what the typical PC programmer is taught, which is to just throw stuff at the GPU and let it handle it.
You probably know what we're talking about here... The Cell processor is a very powerful machine, with the SPEs oriented at vector processing (just like the shader units in the GPU), while the PowerPC AltiVec multi-core architecture used on 'other' consoles is more general purpose. So it is quite a pain to develop high performance applications that work on both consoles.
On one console you have to basically help the GPU operations with some vector processors, but you have a lot of power... On the other you have this powerful GPU but the CPUs are more general purpose!
This is a great time to be in the games industry :)