/r/ is, I think, the defining quality of reddit - it's a very elegant solution to the (x) is turning into (y) problem. /r/truereddit is already a pretty strong contingent of people pining for 06 reddit. But when all the cool redditors start hanging out on /r/truereddit, it will be choked with complaints that it's becoming like vanilla reddit. And thus, http://www.reddit.com/r/truetruereddit
Lots of tabloidy Jerry Springer show sex stuff but also lots of fascinating people too.
I think http://www.reddit.com/r/circlejerk is also great. It's a reddit dedicated to making fun of the rest of reddit. What other site has a section devoted to making fun of itself?
For me, the issue of anonymous vs non-anonymous IAmAs is interesting because it shows some of the flaws of "legacy" PR based on controlling the message. Ideally every organization should move to PR 2.0 and away from controlling the message which would resolves many of the issues, but of course that will take a long time.