Specifically Step 1 of the instructions has a link titled "install node and npm"  which has the line 'git clone git://github.com/ry/node.git', which is incorrect. The correct URL (as far as I can tell) would be 'git://github.com/joyent/node.git'.
In addition the linked instructions say nothing of npm, which can be installed quite easily by running 'curl http://npmjs.org/install.sh | sh' as root.
Back to the TermKit instructions again, and step 5 says 'git clone email@example.com:unconed/TermKit.git --recursive', which didn't work for me. What worked was 'git clone git://github.com/unconed/TermKit.git --recursive'.
Finally after all that, I just see 'You cannot use this version of the application TermKit.app with this version of Mac OS X.'. Would have been nice to mention that at the start.
I generally follow the pattern described here for node: http://blog.nodejs.org/2011/04/04/development-environment/. If you do that, and then install npm as you describe (but as a regular user), then npm will automatically be installed under the node installation.