Maybe I interpret this wrong... sorry, English is NOT my native language...
But it will be a polyglot mess if anyone can start a topic in any language he/she sees fit. It also splits up the community, as English is the common denominator for everyone to use so for everyone to be able to get involved.
I think that every topic should therefore use English, and if a user doesn't speak English it is up to him/her to translate that text, and answer back in English by using a translatror...
It's illogical for me to put up a text in Dutch and expect all of the readers to do their effort. And if more and more topics start in languages I do not understand rightaway, I am not engaging in it anymore... I am getting fed up by people NOT making an effort and therefore forcing ME to take extra steps. It's decency to use a common language EVERYONE (more or less) understands...