From Daring Fireball: Contains Spoilers:

Which is notable in that the new $1299 model sports a CPU that is 16 percent slower than the old one. That is not to say the system itself is "slower", Apple's argument will apparently be that the new Nvidia GPUs more than make up for the difference. What we're seeing may be the beginning of the end of CPU hertz as the rule-of-thumb metric for system performance.

Aside from OS and Firefox bloat -- and games -- there really hasn't been much upwards pressure on CPU performance that I've seen in some time. Even the pressure from games is slowing, in my increasingly uninformed opinion. Oh, sure, it's always better to be able to crunch twice as many SETI@home units, but not required for what most of us do with our computers every day, including programming. The need's simply not there.

For academics and anyone else outside of the corporate-consumerism conglomerate, the reduced pressure on obsolescence should come as wonderful news. My Libretto 50CT still works, so to speak, and there isn't much I can't do on five year-old hardware that I can on new. This is good news for Linux viability, the used computer market, and proponents of universal net access everywhere.