You might want to stick with the separate npm for now if you find yourself using "npm help" a lot.
http://packages.debian.org/sid/nodejs
Ubuntu (11.10) - 0.4.9-1ubuntu3
http://packages.ubuntu.com/oneiric/nodejs
Mint - none
Fedora - none
Arch - 0.6.2-1
http://www.archlinux.org/packages/community/x86_64/nodejs/
Gentoo (unstable) - 0.6.2
http://packages.gentoo.org/package/net-libs/nodejs
OpenSuSE - ??? (couldn't find package database)
FreeBSD - 0.4.12
http://www.freebsd.org/cgi/cvsweb.cgi/ports/www/node/
I tried to get it into Fedora proper, but node currently bundles their own slightly modified libev and c-ares, which is against Fedora's packaging policies.
The npm package has been outdated at 0.2.19 for ages, so this merge will hopefully bring back a usable npm.
You might want to stick with the separate npm for now if you find yourself using "npm help" a lot.