A little of both, there's the constantly evolving system that powers ICHC and the ~50 other sites (not exactly lolcat derivative...the content is pretty diverse) as well as the growing niche social network on cheezburger.com.

One big thing that we're trying to do is make the users' profile pages more of a destination in themselves, where your account on cheezburger is where you express your sense of humor to the world and consume aggregated funny stuff from the people you care about.

A lot of people (myself included) use multiple social networks/online communities for different things. Personal example: Flickr is for my "serious" photos, I use tweetphoto for cameraphone snapshots and bestc.am for more artistic cameraphone creations.

Picture using Twitter for current friends and celebrities, Facebook for family and old high-school friends, and Cheezburger for your online humor friends. Naturally there's overlap (we support sharing your funny stuff on Facebook and Twitter) but we already have a growing number of people who use our (very simple) systems for friending and messaging.