I don't get why the DX11 cards available/not available at Windows 7 launch is even arguable. Nvidia would have loved to have one there, regardless of whether there is any software there, because it would be good PR pure and simple. Not having it might not be a big deal in the end, but you bet your $$ that if they could choose between having it ready at launch or not ready, they'd choose the former every single time

As far as whether the mainstream even understands DX11 in Windows 7 or whatever - of course they don't! But marketing, especially from OEMS, will make sure everyone knows that to get the most hip and up to date system, you've got to go with such and such piece