No; some github worshipper took it on himself to fork xmonad onto github on the grounds that any project not on github is obviously dead and unmaintained and it was up to him to "save" it (this is very nearly word for word from the mailing list discussion!), but somehow nobody actually followed him along the path to salvation and it hasn't been updated since he did it. The official repo is still darcs at http://code.haskell.org/xmonad/ and http://code.haskell.org/XMonadContrib.