As you can see, there is not much happening. In fact, the main lesson learned here was not that a reddit-like platform is not ideal to this type of knowledge pooling, but that the scientific community is in general skeptical about this type of information sharing. We did not require email address validation for logins (hence the spam you can see up there), but we did talk about it with a lot of people and there were good arguments on both sides. I talked with physicists, biologists and mathematicians about using this type of site, and the replies were mostly those of insecurity about sharing incomplete ideas: both because they might be wrong (and not many scientists like that), and because if they were right, they would rather keep it to themselves and publish it.
Actually Paul Ginsparg, the creator of arxiv.org, kind of warned us before we launched that it would take mostly a huge grass-roots effort to get scientists going on something like this. He was right, and from listening to some of his stories about how he started arxiv.org, it apparently took him over 5 years of grass-roots convincing before it took off, despite being clearly a very good idea.
If you are interested in scientific knowledge sharing, with an eye towards collaboration, check out openwetware.org, which uses the mediawiki wiki platform. Note that they actually do require account authentication, so have a lot less spam issues at this point. It seems like a wiki platform is more easily adopted for scientists (although still hesitantly), as the subreddit oww.reddit.com, which we tried to push to the openwetware community, has not taken off (this time because of concerns that Reddit is a company.)