It's worth keeping in mind that there are many levels of language competence and you don't need to be able to carry on a conversation or read great literature in a given language to read most math papers. Personally, with a dictionary (or Google) on-hand, I can follow a French paper or book in my area just fine, albeit much more slowly than I read in English, and I've never formally studied French. I would think the situation is similar for most well-educated Anglophones, though I think many are too intimidated to give it a try.
On the other hand, I can't even get started with Russian since I don't know the alphabet.
