I'm curious to see about the language as well. I'm visiting MUC next week (out from the bay area) and I wouldn't mind meeting some HNfolk, but I don't think my 5.2-word Deutsche vocabulary will cut it.
I'm was in Munich on Monday and in Jena for the rest of the week coming from the Philadelphia area. In general, people speak English very well. I know a little bit of German and try to speak it as much as possible, but people pick up right away I'm not good at it and they start speaking English. I would imagine you'll have no issues at the HN meetup like someone else said, it's an English speaking community.
I don't think this should be a problem. After all, HN is an English-speaking community. What is usually done in such situations is, ask if there are any non-German speakers (or should that be German non-speakers?!) in the group and if yes, switch to English. Private conversations are what they are, of course.
