I think every MacMini from 2006 and newer is faster or much faster. And while being much faster its also MUCH more power efficient and less noisy. The latest MacMini can be equipped with 8 GB of Ram, so RAM shouldn't be a Problem and when Apps with OpenCL support finally come out, speed and efficiency will increase even further.
Yes, but there is still no graphics card in the mac mini which makes a little limited, but I will admit that the intel has made a mark..I have a MBP so I am not against intel or anything, but I do like my G5