A similar thing happened on Imgur when tags were introduced there; it seems to have worked fine on their end, though obviously it's a much larger community. I am not certain how the differences there, much less the differences in culture, would affect the adoption of tags as a means of identifying the nature in which a post is intended.

Additionally, it's worth considering the use of the same system for commenting on posts; there are comment threads out there that I could see having used such a tagging system. The question, then, is whether that would create too much clutter.