Thanks for your comments. The only major problem I found with the Canon Powershot Pro1 is the AF which tends to be a quite unreliable in dim lighting conditions, especially at the tele end of the zoom range. The EVF also tends to freeze until a focus lock is achieved. This can be a problem for fast moving subjects. There is no substitute for a real optical viewfinder like D100's.
Image quality is comparable for both cams, but at higher ISOs, D100 wins again. Not surprising really, considering the smaller imager of the Pro1. The noise level at ISO-400 is still acceptable when making 4R prints though. Any larger than this the noise becomes quite noticeable. You may want to download the pics that I took and print it on your own printer to see if it's acceptable to you or not.
One important factor where the Pro1 wins over the D100 is of course weight and size. It's probably the smallest 8MP prosumer cam out there at the moment. Another factor is the convenience of seeing the pics in all its glorious colours straight out of the camera, with little or no post-processing needed. The D100 here pales in comparison.