Good evolution of "Switch" ads ...
I think the ad looks very good. Watch it (Skandranon has it posted on his Duke edu web site; someone else has it on their iDisk but I wasn't able to get it from there).
This, IMHO, is a gradual evolution, from "everyday dorks" (ie, the rest of us ...😉 ) to minor celebrities to major celebrities. Also, from just the people to what can be done on a Mac (ie, expect more intercut footage, esp when dealing with video industry personalities).
As I said when the ads first started emerging, this "evolution" will be slow, but it will be there. Apple's message has long been that it makes the tool that people who can choose their own tools use. That applies to "everyday folks" in fairly small numbers relative to their PC-oid counterparts, but much more to people who run their own businesses or who are artistic in general. I expect that while we will see more and more "minor celeb" and then "major celeb" ads coming from the campaign, we'll also see more "real people" ads intermixed, to remind us that Apple's not "just" about celebrities and those with money, and that a Mac is waiting for you in your nearest Apple store.
As for not showing the OS X desktop in the ads ... Well, the "Jaws" school of thought (maybe we should call it the Jurrassic Park school of thought to sound more up-to-date) says that if you withhold the payoff in the teaser/ads, the emotional and psychological impact when that payoff is seen is that much greater. Yes, absolutely, OS X is the clincher of the "deal". I have yet to meet someone in real life (ie, not a message-board troll) who was not impressed with at least some aspect of OS X, and I know quite a few absolute Windows bigots. OS X is beautiful, but that beaty would not translate well to a 640x480 max resolution TV screen. It would not have nearly the same effect on TV as it does in real life, and if you "spoil" the effect in a stinkin' TV ad, you've just given away the money shot.
Of course, I'd also kinda like to see OS X and Windows side-by-side in an ad. I just don't think it fits with the Switch theme though (although I may be wrong).