Ironically, when we went the wineries there say they are not really noted for pinot noirs. In fact very few of the wineries make pinot noirs. They say they are better suited for several other types of wines. There are of course a few that do make great pinots, but in the grand scheme of things other grapes apparently do better there.
One of the wineries mentioned in the movie - Firestone - doesn't even make a pinot noir. While we were there, someone came in asking for a pinot noir. When they were told the winery didn't make any, they turned around and left. That was pretty scary to me.
We were there on a weekday and it was pretty quiet - maybe 2-3 people at each winery and many had clearly come out because of Sideways. On the other hand, they said that it can get insane on weekends - with people 4 deep at the tasting bar and the noise so loud that you can't be heard over it - when the masses from LA come up for the weekend. Luckily it's far enough away that they don't come up for just a day.
As an example on the pinot noir, we tried the 3 pinots at the Hitching Post and the first 2 really weren't that good at all. The Highliner - at $50 a bottle - was good but not worth $50. It always struck me as funny that a starving writer would be glugging this down a bottle at a time

On the other hand it strikes me as really funny that he bashes merlot through the movie as undrinkable - but what is his dream wine? The one he savors at the end? It's a merlot.
I'll try to get all my notes and photos up soon!