LinuxTAG was interesting.. I got a better grasp of the Linux and Open Source crowd in Berlin (and in Germany in general). I think my geek-side will be satisfied there. I've decided to check out Sugar-on-a-stick after chatting to them there (and pointed one of the developers in the direction of Numptyphysics, which just may appear as a Sugar package at some point). I'm looking forward to settling down in a proper apartment again, and setting up a media center for myself - A nice ATOM dual core + NVidia (ION) server combination (TEO-X had one there) should provide all the power that I need (with lower power consumption) for XBMC & a retro (& not so retro) gaming setup. :-)
Also interesting was Büro 2.0, which involves a shared workspace and services for Open Source companies and freelancers in Berlin. If I decide to be a freelancer there, this might be an option.