Chocolatey NuGet seems like a great tool, and one that’s long overdue for Windows. Unfortunately, the timing is probably not so great: with the advent of the Windows Store trying to replicate the OSX App Store success, the need for centralized package management on Windows will probably be solved soon.
The great news is that NuGet seems to be focused on open source tools and platforms (node.js, Ruby, etc.) in addition to the commercial ones listed in their package list.
I think the Windows Store will be the dominating marketplace for things like 7zip, Notepad++, etc. when Windows 8 comes out, but the open source/non-Microsoft-compliant market still has plenty of room. Thanks for sharing!