Overall, I think that more effort, as a community, needs to be put into raising the quality of the answers and not answering low quality questions. My point can be summarized as: It seems to me that only bad things can come from answering a question that two rational individuals can interpret completely differently. In situations like that, posting an answer without clarifying does more harm than good, as it can easily mislead future readers of the question. We are all statistics experts and can tell when a question matches that criteria. In that case, my suggestion is seek a minimal amount of clarification from the OP to the point where the question no longer meets that criteria (before answering) and close voting (which seldom happens, see cardinal's data below) if that is unsuccessful rather than just ignoring the question or answering one possible interpretation of it. There are a handful of high-rep users who do this quite well and, I think, lead by example (that's where I learned to do this) but there are others that take little/no role in improving this aspect of the site and their help could improve things.
Here are some other thoughts I have on the subject:
I think a major issue with this site, as opposed to other more populated sites like stackoverflow, is that the close system basically doesn't work here because we have relatively few members with 3000+ rep and even fewer who actively use their close votes. I think I can say, without hyperbole, that I've only observed maybe 10 users cast a close votes (obviously this is biased low, since I only see the votes that result in a closure) other than moderators. This propagates the existence of low-quality questions on the site since - let's face it - the mods are not omniscient.
A second issue, that I can understand happening with inexperienced users of the site but seems less excusable when we're talking about a high-rep user, is that there occasionally is an "post an answer first, ask questions later" attitude, which can result in answers being posted that actually answers a radically different question than the one posed, and, if the question is never clarified by the OP (which happens a fair amount of the time when the OP is a one-time user) can serve as a misleading direction for future readers of the question who interpreted it differently. For this reason, my opinion is that it's important to clarify first, answer second, rather than the other way around.
For example, in the question which motivated this meta thread - here - it is my opinion that much more information is required to answer the question correctly. The answer posted there may be correct, but we have no way of knowing and, if a future reader interpreted the question differently from the answerer, such an answer may mislead them, since there's no mention of the scope of the answer at all. So, another suggestion I may offer is: If you're going to answer a vague question, at least clarify what your interpretion of the question was.