The latest version of node.js is available for the FS.
You can find it here: http://www.droboports.com/app-repository/nodejs-0-8-4
Thanks to Jason Schmidt for breaking the ground with his very helpful blog post, which you can find here: http://zannalov.com/net/nodejs-on-the-drobo/
As far as I tested, everything works including npm.
As usual, comments, suggestions and feedback are welcome.