This weekend I finished my first sprint on s3p which is a Python library and CLI application that manages release pipelines on AWS S3. I put a lot of effort into the readme.rst file, so look there for usage and examples.
The main purpose of s3p is to use code to enforce process when promoting releases in the pipeline. Another goal was to make the CLI tool dead simple to use. As a side effect, I ended up using composition to extend boto.s3's Key and Bucket classes to produce S3Release and S3Pipeline.
I plan to incorporate s3p into Teamcity build jobs. At work I would like to use s3p to replace bash+s3cmd in pipeline management. Once s3p has a bit more production use, I will likely sprint on it again.