Is this really the biggest improvement in MacBook history??
It is worth pointing out, the only people that will seriously notice the boost are multimedia professionals and hardcore gamers. And even then, it is a boost.
Everybody else can relax. It does make sense to wait if you can, but if you can't - well, a few years ago, an old processor and limited RAM could potentially kill you, as the web was rapidly getting richer and more complicated. But with the proliferation of smart phones, netbooks and low-powered tablets like the iPad...things are actually getting optimized for lower-power computing. The web, productivity software, and even operating systems. It is unlikely most people are going to be feeling squeezed by their Core2Duo machines anytime soon.