Hmmm... Will probably be flamed for this one but anyway
I feel that my post was fully justified. I was talking about real life scenarios and still stand by my comments on processor usages and ram. 64 bit windowed applications, the ones that mainstream users will use, will start to appear after the introduction of Leopard next year but don't you think that they will take a while to take off?? But seriously 64 bit number crunching apps would be more suited to desktop machines anyway.
The main issue that Apple is trying to overcome is heat. The Macbook Pro runs hot enough as it is and it is pretty obvious that the way it is cooled is only just effective with the current model. Putting a Core 2 duo in it (running your 64 bit apps at full processor utililisation

), a newer model graphics card and up to 8 gigs of ram will only add to that. A re-design of the cooling system is what's needed to accommodate new components .
Maybe a new form factor is around the corner....
aussie_geek