A couple weeks ago we had bid fare well to the Power Mac G5 and while I was considering replacing it with a MacBook Pro, I eventually went with a Mac Mini, making it the 3rd one in the house (there were already Tom's G4 based mini, and the Media Center Core Solo based mini).
The newest addition is a 2 GHz Core-2-Duo based mini, upgraded to 2 GB RAM; and having all the other minis around, makes it easy to compare things like speed, runtime temperature, etc. and since I did the memory upgrade myself, we also looked inside, comparing the internals.