Thanks for the replies. The amount of cash is not the real issue. I just don't want to spend more on a machine that will be too much for what I need to do now. Given that nehalem will be out in a year or so...it seems silly to buy an overpowered machine for future proofing...when the future machine will be much faster.
Portability and weight also come into it.
I will be getting two 23 inch ACDs to go with it.
One ACD is to use with my PC...for games...and the other for the MB.