This is good news: https://buildd.debian.org/status/package.php?p=nodejs&suite=experimental
It's currently not building on armel, but it looks like a simple configuration issue. If anyone has an armel chroot to hand perhaps they'd like to test a patch and reply to bug #772023. Nodejs is one of the top four blockers on arm64 according to my (non-authoritative) list. Here's the top of the list with the corresponding counts of BD-Uninstallable packages: 40 golang 26 mono 21 fpc 21 nodejs 11 arm64:libphobos-dev 6 dietlibc