Okay I know I'm going to get flamed for this but... so what? Seriously, how many people, even on this site, are REALLY going to notice the difference day-to-day between the processors of 9 months ago and today? I, for example, am currently running a 3 year old 17" MBP and while I do want a new machine it's for reliability reasons rather than speed. I've never, not once in three years, thought 'I wish this machine was faster'.
Sure, pro's who use their machines heavily day in, day out may notice the difference between a high end Core 2 Duo and a i5 or i7 but the VAST majority of buyers just won't care. And there's a lot to be said for keeping hardware stable for extended periods of time too: there should be fewer unforseen issues and more time to correct production issues if / when they occur. It's easier to narrow down any problems that occur in OS X when you've got a more limited range of hardware to support. And of course it makes it easier for people to plan their purchases if they DO care about hardware as Apple are fairly easy to predict compared to other PC makers out there.
Basically, for the average user, providing the hardware is quick enough not to be a noticeable drag the exact specs are irrelevant. This didn't used to be the case but there hasn't been an explosion in computing power for years now and even if there were the vast majority of tasks run on todays computers wouldn't need that boost anyway. So why do people get so upset about this? If you know enough to care then you can certainly find out when upgrades are likely and not make any purchase in that time frame. Simple.