As I said, I'd start by adding a LW section to the other two pages. This should not be a problem, since the notability standard is not nearly as strict for the content. Once the section grows large enough, you can add a notice suggesting a separate entry and see how it is received.
LessWrong is a great resource. It gets a fair amount of traffic (800,000 pageviews per month back when pageview-counting was working properly), has a large number of people identifying as part of the online community (2013 survey results), and has a number of lurkers including high school students (see this post). And yet, it doesn't have a Wikipedia page of its own. LessWrong on Wikipedia currently goes to Eliezer Yudkowsky's page, which has a sentence devoted to LessWrong.
The main reason for the absence of the page is that LessWrong hasn't received enough coverage in the media, so it wouldn't pass Wikipedia's notability criteria. Even if one of us created a page on LessWrong, it would get speedily deleted because there wouldn't be any reliable sources to cite.
So, question: any ideas on how to generate media coverage for LessWrong, enough that it passes the notability criteria of Wikipedia and can be given its own page? The media coverage will help directly in addition to being useful to creating a Wikipedia page. The Wikipedia page itself will help portray LessWrong as "legit" and also provide information to people that'll help them decide if the site is suitable for them.