This is probably the most intelligent post I've seen in a long time.
I think there is still room, although some might say that "tube" sites and blogs are the way to go over TGPs. Me, I like TGPs.
Instead of registering 15+ domains and trying to get all of them off the ground, I would suggest focusing your energies on one site, whether it be a TGP, tube, or blog. That way you can focus on quality design, quality content, setting up some good trades, and building your PR. That's my
Best of luck!