Is Prog fan base getting older and older?

This pretty much sums it for me as well. That's not to say it's written in stone and that there are no exceptions to the rule but generally speaking this seems to be the case more times than not. Also, to some degree it depends on the band and the exposure the band gets in the mainstream. For example Rush and Pink Floyd both seem to have a lot of younger fans(I'm talking about really big fans too not just casual ones). When I saw Roger Waters last year there were plenty of people in their twenties and thirties there. It would actually be hard to pinpoint the average age since there were so many people of varying ages. With Rush it was also true but with probably less women(although to be fair I do feel they have made strides in that dept).  For whatever reason, Yes, on the other hand doesn't seem to have nearly as many younger fans. There seems to be a few here and there but the last few times I've seen them it seemed like there were very few people there under 40(heck even under 50). Genesis seems to have a rather mixed fanbase as well with quite a few women in attendance(when I saw them)but I'm guessing most of the women(not to sound sexist here so please don't get angry)and most of the younger fans are mostly in it for the later pop stuff. Then you have a band like Ozric Tentacles who have several older fans(late forties and fifties on up)and lot's of younger fans. The older fans seem to be the prog heads while most of the younger fans probably got into them through them also being sometimes labelled a jam band(just a guess here). Porcupine Tree have or had a lot of younger fans but it seems to me that most of them got into the band through their Opeth/Mikael and metal connections.