I vote against a german forum, both as a stand-alone or as a sub-forum in here for all the reasons Whimsical, Per and Nik Sha mentioned.
(Decentralizing of knowledge or some knowledge becoming exclusive to certain groups)
Additionaly, I have to admit, I fail to see its merits… when you try to become a programmer, english is a key-skill to have. The sooner you take that to heart and deal with it, the better for you. Providing platforms for the different native languages only obfuscates this cruel truth. 
Of course it’s a bit more demanding (even after years of hanging out in english comunities I sometimes have to search for the right words and dict.leo.org is always open in my browser), but learning a language in an interesting context of your choice is still much more fun than in school.
Also, I myself greatly dislike hitting some glibberish talk when browsing an international site… even if it’s in it’s own sub-forum, others will still accidently stumble across it via the search-funktion.
On might argue that if I don’t understand it it most likely doesn’t concern me. But I’m awfully curious!!! XD So I’d like to judge that for myself. So even if indeed it doesn’t really concern me, I feel it’s profoundly rude to not let me know what’s being talked about.
… and the little english summary of each post siggi-gross proposed already takes up so much discipline, I can’t see this happening… :?
However, I really like the idea of organizing local Unity-meetings and I think it would be a good idea to set up a sub-forum for this kind of stuff here.
(For the stated reasons I’d personally prefer to see these threads be in english, too, but I suppose one could make an exception for those…)
And yes, I’m really german 
Und ja, ich bin tatsächlich auch Deutsch 
Hab’ auch die ersten Jahre Englisch in der Schule gehasst wie den Tod, aber seit ich in der siebten Klasse gemerkt hab, dass
a) Filme und Computerspiele auf Englisch sehr viel besser sind,
b) es die richtig guten Animes nur mit englischen Untertiteln gibt,
c) man mit dieser Sprache tatsächlich deutlich leichter Programme lernen kann
und nicht zu letzt
d) Französisch viel schlimmer ist, :roll:
hab ich die Sprache doch lieben gelernt… 
Greetz, Ky.