I'm still a big believer that people will pay for quality, but the whole tube issue couldn't of come at a worse time. With the down economy, Im willing to bet that a lot of people are relying on tube sites for their fap material so they can avoid a $35/mo+ charge.
Since it appears that most tube sites are banking from dating sites and pushing cams, my guess is one of two things will happen... either tubes sites will crumble with the cost that is involved with bandwidth and the ever so tanking conversion rate of dating sites, but that is probably 3-5 years down the road.
Second guess is that a large amount of these tube sites are own by programs themselves, so once they get your email addy, they just spam the hell out of you until you pay for a membership with 400 prechecked cross sales
Honestly tho, here is my

... there is only so much content on tube sites for niches. A lot of my sales from are still strong from niche sites I push, but general hardcore sites have been on the drop for over 3 years now. I really only push those sites just to filter traffic into my niche sites.
I think its a case of history repeating itself here with the advent of TGP/MGPs coming out. Hell, you could download all 4 video clips and have yourself a nice 2 minute wanking period on repeat. Now you can download a full 30 minute video, but how many times can you beat off to the same 30 minute video which is probably made up of the first 1/2 she is talking and doing a strip tease?
One thing i would be curious to know is the amount of churn for "general" sites over the past 2 years. My guess is its probably down, meaning members stay on longer. Why? because those people looking to pay $3 or $5 for a 2 day pass to try and download all the material, are now doing it for free.