Node.js 0.11.8 is out (released on 30 October, 2013), and has a source tarball available. Most likely all it requires is a rename of the ebuild. I will check and report back.
+ 14 Nov 2013; Patrick Lauer <patrick@gentoo.org> +nodejs-0.10.22.ebuild, + +nodejs-0.11.8.ebuild: + Bump for #490596