
Adverts *did* say not all features are available on all versions, small print yes, but common sense should be applied, just because these people plead ignorance doesn't mean that their claim is valid, if you see an advert for a car for sale you should always ask "what will I get with it", alloys power steering, abs, aircon, metalic paint, leather etc. etc. etc.
The litigous nature of americans is either driven by stupidity or greed, not a sense of right and wrong, remember the woman who (successfully) sued McDonalds for making their coffee too hot (nasty burn, but who's fault was it?)
Should society stop supporting stupidity? If you buy a product without being sure it does what you want (either through knowing or asking), then tough, imagine if they won their lawsuit, had millions awarded, who would pay? the people who buy Windows 7 of course, this would never be a punishment for Microsoft, where does their money come from?
Vista is way more than Aero;
http://en.wikipedia.org/wiki/Features_new_to_Windows_Vista
But you can't advertise the fact that the windows address book is based on XML as a feature, as it's a bit boring, adverts are visual and snappy, so you need to show visual and snappy, almost every car advert has cars with alloy wheels, but nobody (in their right mind) expects alloy wheels free.
Maybe in a country with an average IQ of 98 (and dropping) you need to spoon-feed people but perhaps a better solution for society as a whole is to stop them breeding.