Hey Christoph,
Not sure if this would help you, but I've playing with the idea of extracting some of the functionality that Org babel provides and created a small tool for doing reproducible runs using Org mode syntax:
https://gist.github.com/wallyqs/10989253
It is based on the Org ruby parser implementation so not all the latest syntax and features are covered...
I named it `org-converge` in the sense that a reproducible run should converge into the same result, and also because in the long run I hope to achieve some similar functionality (or at least wrap around) what is possible to do currently with tools like chef, ansible etc...
I' ve found it useful for doing reproducible runs along with other tools like Chef and Capistrano, and also for some development work. If you have some ideas or feature requests the feedback is welcome :)
Hope this helps,
- Wally