Feedback Wanted on Python Build System

After being a bit frustrated with both command line tools such as Fabric as well as build utilities like SCons, I thought I'd spend a bit of time thinking about what would make an awesome build utility for Python. I modeled a lot of it after Rake, due to its immense popularity. However, I distinctly tried to make things more explicit and more Pythonic. I created an example script that would be fed to this new tool.

http://pastebin.com/8j8FUYSd

I'd like to hear any feedback you might have on this. Would you like a tool such as this? What do you like or dislike about this format? What features do you really like from Fabric, SConstruct, or Rake?