The ability to invite people to see drafts would be an interesting one, that would make this sort of writing group much easier to do. (Basically, posting a draft to discussion without posting a draft to discussion.)
Yes, but then we'd also need a place to discuss them... and the discussions wouldn't be appropriate because not only do people hate meta threads but it would also give away the content of the post and defeat the purpose of limiting exposure to refine the piece first. Also, from what I gather, it's relatively hard to get changes made to the website. The best route is apparently to just make them and then hope that Luke or somebody likes them enough to implement.
What would be much easier in this case is to simply throw a private open source message board a...
Ever since Eliezer, Yvain, and myself stopped posting regularly, LW's front page has mostly been populated by meta posts. (The Discussion section is still abuzz with interesting content, though, including original research.)
Luckily, many LWers are posting potentially front-page-worthy content to their own blogs.
Below are some recent-ish highlights outside Less Wrong, for your reading enjoyment. I've added an * to my personal favorites.
Overcoming Bias (Robin Hanson, Rob Wiblin, Katja Grace, Carl Shulman)