I've watched this ad, and I noticed a few things, and it brought up some information I already knew.
1) She Picked Apple First. Why?
She's an actress, and a member of SAG (Screen Actors Guild). Hollywood primarily uses Apple in their productions, and on screen. Getting rights to use Apple products are a lot easier than getting the rights to a Dell product, which uses Microsoft and a host of other vendors. That's why you don't see a lot of TV and movies using PC's; notice that they use Macs if they can.
She's familiar with using Mac's from her work as an actress on a set.
2) Why did she want a 17" Screen?
To be honest, I'm not sure. For checking emails, and doing some minor multimedia, and web surfing, a 17" screen seems a bit overkill...Then again, why do we want the 50" HDTV vs the 32"? Because it's bigger.
3) What criteria did she use to pick out her PC?
According to the ad, price, screen size, speed, and aesthetics, but you could tell her sole motivation was screen size and price. The other criteria she mentioned were supporting her rationalization, and no other criteria mentioned. Essentially like buying a toaster, or a blender.
4) What didn't the ad mention?
No additional warranty on the HP she bought; just the HP one year parts/labor. No Office suite; no Anti-Virus security package; no additional multimedia software. This is what's left out to get a "bargain basement" price on these Worst Buy laptops.
5) Is Microsoft desperate and worried?
From this ad, they sure are. Vista dug a big hole for them, and the Apple ads made it even bigger. Also, they're trading at $18.37 a share today, whereas Apple at $105.12 is quite good.
Yet the interesting thing is, this ad made them out to be the "cheap" option, which I don't know about you, but I wouldn't want to be associated as a "cheap" manufacturer of a product, because my product comes off as being cheap just as much as the cost might be cheap.
6) Will Apple ever develop low-cost units to compete with?
No. To do this, they would either license OSX to a PC house like Dell or they'd have to go the "clone" route, which had disastrous consequences the first time around. Neither one of these are likely, as it would dilute the Apple brand.
This is why you don't find BMW, Mercedes, Alfa-Romeo, Bentley or Rolls-Royce making vehicles less than $30,000. You're paying for a higher end experience.