A Kickstarter for dev tools would be a great idea. As well as new projects, it could also be beneficial for large changes to existing projects. Some combination of Kickstarter and bounties for GitHub issues would be interesting.

My only concern would be for the potential drama caused by members of the community who find the idea of paying for open-source development abhorrent.

Why does the script need to be in Python? Isn't Fake S3 just a server that you run and connect to from any codebase? I'm curious because Python is the language I use most, but I could easily see myself writing a Fake S3 in golang or clojure or even C.