ok, as a language teacher I have to say that I find 'literacy' and 'fluency' to be two rather different things, and I think that the JLPT, seeing as it does not test Speaking (which is a main component of fluency), it is not a very good test of fluency, but rather is a test for literacy. I also know people who are fluent in Japanese but wouldn't test well on the JLPT (actually I have a friend whose first language is Japanese, but thinks he failed N2 last week!). To me, the JLPT is a test on test-taking. That's not saying it's not a measure for language ability by any means, it's just not a test on common-knowledge Japanese, or a measure of how well you'd survive in Japan. It's a test of how well you remember all the picky little grammar patterns and obscure vocabulary words that aren't used in daily conversation (this is more about the N1 than the N2 though, but it still applies to the latter).
That being said, if I hear that someone has passed the N2, I'd have the impression that they were at least conversational in Japanese - it is, after all, a requirement for most colleges in Japan for matriculating non-Japanese students, as well as for many jobs in Japan for foreigners. It is definitely an accomplishment! Just conversely, I would not look poorly on someone who had *not* passed, because it doesn't necessarily have that much a bearing on someone's actual fluency.
I hope that all made sense. I should get down off my soapbox now...