just in case someone more often reads the english forums than the rarely used german section: I've just finished my german siena locale which I'd like to share with you for testing. Informal version, core, modules, plugins and standard themes included.
Because my site still runs on genoa and probably will do it a while, I cannot fully test each and every string for errors yet. However, most things should work for now and the rest are small bugs. Once the pakage becomes as correct as possible, I'll put it into the official download section. Or maybe I'll contribute to the SVN, depending on my time to engage with versioning systems.
Corrections and comments welcome!
Steffen aka Schulle4u