Regarding the movie, the main message I took away is the power of popular entertainment to influence popular tastes. Who would have believed that a throwaway line in a mild Hollywood comedy would lead us to such phenomena as pinot noir from Corsica?
Oh, I agree wholeheartedly with your point about the power of popular entertainment...but I would offer the counterpoint that living in the moment tends to exaggerate effects, and the popular taste can be not only damned fickle, but repetitive and cyclical.
Case in point: years ago, there was Le Sable Pinot Noir from...wait for it, wait for it....Algeria. Rough as a cob, thin and sharp, barely recognizable as Pinot Noir, and got down to $2.99 a bottle pretty much every day. End case stacks in grocery stores were quite common.
Another case in point: back then there was plenty of el cheapo Pinot Noir from the Iron Block satellite countries in Eastern Europe, mostly Bulgarian as I remember. And it was pretty terrible stuff.
Case in point, more immediate: long before the movie came out, Cavit was bringing in 1.5Ls of Pinot Noir (or you can call it Pinot Nero, but you doesn't have to call it good). My company came out with a Languedoc Pinot Noir....but that was planned well before the movie had any impact on the public consciousness.
Which brings us to the point: long before the movie came out, and much longer than it had any chance to create trends, PINOT NOIR WAS ALREADY SHOWING MAJOR UP TRENDS!. Yes, the last year has shown a significant jump in growth, but it's been up big time since the early part of the century.
And let us not forget that one major reason there's a lot of Pinot Noir being sold is for the first time in the US there's enough load-bearing Pinot Noir vines coming on line to supply the growth. But that didn't happen overnight: it was planned and developed over a period of years.
So Sideways may have (and I think DID) create a flashpoint of growth---but it was built on plans developed and implemented years ago that allowed that to happen.