If you look at a high enough level of abstraction, the current series of GP-GPUs are basically a large collection of vector processors with a fast interconnect

If you look at a high enough level of abstraction, the current series of GP-GPUs are basically a large collection of vector processors with a fast interconnect between them -- one that mirrors the mechanism Cray used in its supercomputing system (X-MP, Y-MP). The main difference is one of scale. These are currently limited in scope of applications, but they are very well suited to applications that were formerly the domain of specialized vector supercomputers, so I think that they will be big in supercomputing even if they don't grow in versatility. However, I think that they will, especially with Intel getting into the biz. Intel may not very good at building graphics processors and drivers, but Intel is VERY good at building on-chip interconnects, small processors, and very fast on-die caches. That ought to make for some interesting competition, since nVidia and AMD aren't constrained by the x86 ISA, while Intel is.