The Core2Duo era isn't really over, the platform is simply evolving on Intel's 'tick tock' manufacture/design cycle & being rebranded to bring it inline with their desktop products.
Yeah, there are, but the iMac's now have the i5 and i7 as the higher end models. I imagine the next update will see the base iMac become an i3 with some CPU bumps to the i5 and i7 models. Of course proof is in the eating of the pudding when it's plated
.My thoughts on the notebook market are that it doesn't matter what manufacturers of end products want to do, they're generally limited to what the component manufacturers are developing and producing, and at the moment the technology available is dual core systems designed for low power use applications - which trace their heritage back to the Mobile Pentium/Centrino series.
Personally I see that dual core is the most pratical 'best of' solution for laptops - it keeps the power useage/performance balance. The real gains in processor 'speed' are not Ghz - as we all know - but rather in improving the instruction sets and taking advantage of/using threads. The next dozen or more years are going to be all about developers getting out of the single thread mindset and using tools like Grand Central Dispatch to make their applications better at processing data.
Companies like Dell are hardly what I would consider innovators in the field - they outsource battery components compared to Apple actually working on their own units (or with third party supplier) to improve battery life.
At any rate, my current C2D 2.4GHz Late 08 MBP 15" is sufficient, especially as I only use it for generic web surfing - my i7 iMac is a great desktop unit. The only thing that appeals to me from the new MBP is the momentum scrolling and high res display. If I could afford the switch and used my laptop more than I do, I'd probably be doing it