It was my impression that he didn't really want these blogs or identities associated so strongly. Respecting his wishes for increased privacy-by-obscurity would suggest not discussing these blogs by name openly.
[Edit: My points still stand, but this isn't an issue worth fighting over. I've gone back and edited my post.]
Good point, although I think that by this point that ship has already sailed. That said, if people really think that it is an issue I will redact the name of his old blog. Note, however, that Yvain's old Less Wrong posts are heavily sprinkled with links to things on his blog, so its not like they are remotely unconnected.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.