1) There's Photoshop CS4, which seems to be taking advantage of it.
2) It's not a programming language. It's a platform... kind of. I'll say IDE.
3) It uses the GPU as the processor instead of the CPU. Which means pure number crunching goodness.
4) Nope.
__________________
cChip interpreter WIP - current status: Release Candidate
LRx Filter RC - current performance rating: 9/10