it would lead to fragmentation, with different sub-monasteries emerging around each language

Not necessarily. I was faced with this issue when I designed the UN's first web-based discussion forum (with perl naturally) over ten years ago. We decided to have multi-lingual fora where everyone was free to post in their own language and filters which allowed users to read the boards in all languages or only in one. What ended up happening is something similar to what is happening in this very thread. What starts out in one language leaks over to other languages due to the people who speak several languages. There were also many people whose reading fluency was better than their writing fluency (a common occurrence) so that people would end up reading the English and replying in French, etc. And perhaps the most important thing was that the participants, even if they could not all understand each other, had the sense that they were all part of one world, one discussion. (so shoot me, I'm a romatic idealist)

The really important question for me is the question of inclusivity. I would like this to be a place where people of all levels of language ability could participate. It could even become a way for people to learn some of the tech aspects of English and the other languages. I get by pretty well in French but not with French/Geek since I learned my French long before I knew anything about computers.

It seems to me that it is no accident that this discussion is sparked by someone from Brazil instead of someone from Portugal or Holland or Germany. Europeans are more likely to know some English than Brazilians are. But the future is in Brazil and Japan, and China and India and Singapore and South Africa and hopefully other places as well. Inclusivity is not just a matter of making accomodations to incude the excluded for the sake of the excluded, it is and will increasingly become a way for the English speaking to broaden their horizons and gain from the diversity of the worldwide open source movement.

I don't at all pretend that it would be easy to make perlmonks multi-lingual or that it is something we can or should start on immediately. But certainly we need to start thinking about it now, for our own sakes, as well as for the sakes of those who could not participate here otherwise.