I'm sometimes reminded by Yehuda that exposing basic checks and constants the browser has is useful. So if #43 gets implemented we should consider exposing "XML MIME type", "JSON MIME type", "JavaScript MIME type", et al.

Given that sometimes this involves an "ends with" match on the subtype it doesn't seem like just exposing the array of MIME types is the way to go.

This leaves us with either static or instance methods. I don't have a strong opinion either way. If someone can find compelling precedents that'd be most welcome.