Well after that part either you find something about their work interesting or vice versa, or you look for some other common interest, or you go your separate ways...
Having met a few programmers in the wild, topics of interest come up and languages themselves aren't interesting. However, differences in languages, or where languages fail, sometimes come up.
Personally, leading with a language is superficial at best, and at worst, a crude filter employed to determine whether or not a person fits in with your objective or clique.
This happens -all- the time at reddit meetups. We're clearly a group of mostly programmers and techy people, yet everyone describes their profession as "programming." I have to pry out what they actually do. That said, benologist has the right idea with asking what they do rather than how they do it.