Instead of describing the commercial frame by frame like so many other sites tiresomely do, let's just look at it (HD version):
The obvious message in the commercial is of course that Lauren can get more bang for her buck by buying a Windows laptop. The commercial also accentuates that Lauren has a lot more choice when shopping for a Windows laptop - we get to see dozens of them lined up, whereas there was only one Mac for her 1000 USD budget.
What I like about the commercial is the authentic feel - they didn't use sets or studios, but real shops and locations. There's also a lot not to like about it. The music is corny, and I really don't like it when actors in commercials are all "look at me being all average and normal like you!" There's also a very odd moment in there, when she sighs "I'm just not cool enough to be a Mac person..." They should've replaced "cool" with "rich" and it would've made much more sense. Now she just admits that you have to have a Mac to be cool, which doesn't sound like a good idea if you want to discourage people from buying... Macs. The final line is very good, though: "I'm a PC, and I got just what I wanted."
Still, in the current economic climate, it makes perfect sense to focus on the fact that you can get more PC for your money if you go for a Windows machine. Data from the first two months (January, February) of this year have shown that Apple has seen a rather harsh decline in sales, with Windows PCs and netbooks specifically seeing steep rises, probably because you can get those cheaper. However, the figures for March will tell us a lot more, since those will include the sales after Apple's desktop refresh.