Windows Compatibility 

Added node dependencies:
Archiver - Used for zipping
BufferStream - Used to stream the output of the archiver into memory
Wrench - No hassle recursive file operations

Removed dependencies:
*NIX operating system
zip command line utility

I had to upgrade the node min version from 0.6.x to 0.7.x because of the new "fs" operations. I have tested these changes (using text/index.js) on both Windows 7 and Ubuntu 12.04. Both were able to produce a crx file that could be installed in Chrome. I upgraded the package from 0.2.9 -> 0.3.0, because this is a pretty big change and it will break people using very old versions of node. 

Other misc. things:
Keygen from the command line wasn't working because commander doesn't provide a callback as the second parameter - this is fixed
I changed path.exists to fs.exists to get rid of a deprecated warning
I added "manifest_version": 2 to your example extension - this is required in the latest versions of chrome

Let me know if you need me to change anything, or if you see any problems.