http://www.armpits.com just launched in the past couple of weeks. I didn't realize how much I was into armpits until I started cruising the site.

And then these have been on the board lately:

http://www.beastpaint.com

http://www.fursuitsex.com/

There's also http://www.older4me.com, which is mostly 50+ year-old guys

http://www.fistingcentral.com I don't know if fisting counts as a niche or micro niche.

http://www.gayfruit.com is a site totally devoted to Polish gay twinks.

http://www.dungeonbears.com/ is, well, bears and dungeons.

http://www.workinmenmovies.com/main.html is largely redneck kind of guys.

http://www.chubvideos.com/ is big, big, big men.

http://www.sleepingmen.com/ watching guys with night-vision glasses/camera.

And Condom Cash has a whole mess of micro niches.

Those are pretty micro, I think.

Cheers,
Michael