I have no idea what sort of performance is available but, for example my i3-540 CPU says it has a 733Mhz Intel HD Graphics GPU in it.
Anyone got any idea if these would help with any sort of GPU or CPU mining?
Intel hasn't provided OpenCL support for their GPU and I am not sure if they even use unified shaders.
The gaming performance is very very very very very very bad. The cheapest crap integrated video from either AMD or NVidia utterly annihilates Intel HD Graphics GPU.
Ballpark figures:
So if someday Intel got off their ass and wrote OpenCL support for their graphics cores ... AMD slowest on CPU graphic chip (fusion APUs) does about 25 MH/s. Intel is likely at best half that. Realisticly give how little Intel seems to care about even decent graphics performance I would say maybe 30% of that is more realistic. However today performance is exactly 0 MH/s because Intel has no OpenCL drivers for any of their GPUs.