4.4.0 is the current LTS release of Node.js so IMHO it would make sense to stabilise it in Gentoo... Moreover, the current stable version of net-libs/nodejs (0.12.6) appears to contain a Denial of Service vulnerability - please see bug #568900.
In order to make net-libs/nodejs-4.4.0 stable it would also be necessary to stabilise dev-libs/libuv-1.8.0 and either net-libs/http-parser-2.6.1 or net-libs/http-parser-2.6.2.
this is being done entirely at bug 568900
*** This bug has been marked as a duplicate of bug 568900 ***