No, but you also need to have a very clear design which transmits a mental model of how your site operates. I'd be skeptical of a site that was messy and over cluttered especially if I was going to be using it to trade knowledge!
I think a clinical, empty look wouldn't do, but adding more mess is the wrong direction.
If clutter made it harder to form a mental model then everyone in Vegas would be lost.
edit: But the reason everyone isn't lost is because Vegas is basically one straight road with flashing lights on the sides. Which is more or less what I'm proposing.
Also, I see your point about the knowledge seeking demographic. Not sure whether I agree or not. For every Jimbo Wales looking to hire a philosophy postdoc, there could be a hundred MySpacers looking to hire someone to clean out their bongs. Or maybe not, who knows.
Also, on a different topic, there should be a way to embed ads for experts onto my blog or homepage.
Thanks - this is on our to-do list as well. You could use SpringWidgets now but we'll probably make a Digg type widget down the road and let bloggers embed referral codes in it.
I think a clinical, empty look wouldn't do, but adding more mess is the wrong direction.