Thanks to @bazza and @stankea, WordPress.org has been fully migrated to nginx from Litespeed and Apache. Please let me know if you find things wonky with anything on wordpress.org, api.wordpress.org, bbpress.org, buddypress.org, etc. (Beyond the usual wonkiness, of course.)
The only known issue is that query strings were temporarily broken on translate.wordpress.org. The rewrite rule has been fixed.