The Apple “Get a Mac” ads use the same methodology as the political "jokes" that right-wing associates send me. They both attempt to spread a false meme by using it as the premise for humor on the hope that if you laugh at the joke you’ll assume that the premise is true.
In the case of the right-wing smear jokes it’s things like "Obama’s a Muslim" or "Obama’s a terrorist" or, back in the 2000 primaries, "John McCain has an illegitimate mixed-race child".
In the case of Apple’s smear ads it’s things like "Vista is unusable" or "If you want to run Vista you’ll need to replace all your hardware" or "If you use Windows you’ll be flooded with viruses"
Both can be effective but both show an inherent lack of concern for honesty and a contempt for their base.