To give you an idea of how much power is under the hood on these puppies, the Octane III sports up to 20 Intel processors and one terabyte of memory. All this for $8000, which is a lot of processing bang for the buck.
For certain niches businesses, Cray or Silicon Graphics offerings will put supercomputing within reach of a lot of smaller businesses.
For any company working with HD, it would takes this kind of power to render video or graphics, for example.
It would also help certain R&D companies that need to do some serious data crunching.