A few other things may help increase Apple sales of Macs:
1. Rightfully or wrongfully, they own the portable mp3 player market, to the point I say "my iPod is a generic"
2. iPhone.
3. Snow Leopard recently came out, with coinciding other software updates.
4. And I think the biggest reason, the prices of Macs are really pretty cheap, in comparison. You can get a Macbook pro (which, all Apple-bashing aside, is a nice fast machine, good graphics, bluetooth, rugged lightweight coffeehouse-friendly sort of thing) for less than my (pre-recession) monthly toss-around $ allowance.
Yeah there are cheapy windows laptops that'll do the things people use their computers for. But for a little more money you can get something nice that's not pre-loaded with bloatware, won't get you in virus trouble, looks and feels better than most windows laptops on the market. Think of what *most* people do on a laptop - a mac does a great job for that.
I'm not sayin they're the best machines for everyone. But the density of MS fanbois here, clamoring to suck up to Bill Gates' machine...