Although I was too lazy to express it, these were my thoughts precisely.The Core 2 Quad as it stands now is not very power-efficient compared to the Core 2 Duo. This is mainly because the Core 2 Quad is designed in the same way the Pentium D was: 2 processors sandwiched together. In the Core 2 Quad's case, it's basically two Core 2 Duos sandwiched together, effectively giving you two dual core CPUs, aka "quad core". Because of this, it's not very efficient when it comes to power savings.
However, I'm sure this will change once Intel comes out with their true quad-core CPU, in which that the die will have 4 cores....not 2 dies with 2 cores each. When this true quad core comes out probably later this year, we might see some mobile versions that would be more power-efficient, thereby possibly making their way to the MacBooks and MacBook Pros.
Bob you just proved my earlier point about RAM prices. Take this OWC RAM for G5 PowerMacs. Sure it is only 2G but for 2 to make 4G the price is so much cheaper. It all boils down to Apple decision to use server style RAM in Mac Pros.