I'm a javascripter but in recent years, I had no choice but to work with ruby/rails for server-side things.
Now that node as arrived, I consider it's heading the same way that ruby is with the way it manages its packages. Npm is a rubygem-like manager but I have been frustrated over the years with gems because it's a central repository that can go really wrong if you mess with it. I had problems on when I tried Ruby1.9 and when I moved to Rails 3 because everything is central and if a config changes, it can break it all. Sometimes, I feel stuck in rubygems-hell like I was stuck in DLL-hell back in the days.
I would want node.js to avoid central repositories and I would prefer projects be stand-alone : you clone it and you run it in its own environment. That means having the right node version in a "bin" directory but also having modules installed in its subdirectories.
Example, if you have three projects using Express, you'll have 3 copies of Express, one in each of the subdirs of the projects.
Would you use that kind of package manager?
http://book.git-scm.com/5_submodules.html