That definition of intelligent discussion was mainly content-based, rather than form-based ("discuss a subject other than..."). Seeing as the question is dealing with content as the second variable - an interest or non-interest - it's not a particularly useful definition in this instance. I'd define intelligent discussion as one where information is shared with the intention of updating beliefs, challenging current thought and developing models of reality.
This could be in any area, and yes - I would rather prefer that type of discussion in any area than stale, useless small chat about a topic I am interested in. Because I like to *stay* interested in my interests, and such small chat is very likely to do the opposite.