Don't know exactly why it took so long for this interview to go up, but the folks at elbakin.net just posted the interview they did with the author back in the summer of 2012 on their website! Here's a teaser:
You spoke about humor in your script. There is a lot of humor in the Malazan series. Do you envision it as a comic relief or is it really a part of the series, something meaningful?
In many respects, I’m not writing fantasy with tragic elements, I’m writing tragedies with fantastic elements. But you have to relieve the pressure for the reader, and for me, because if I were to sustain that pressure for 320 000 words per book, that will be just overwhelming for both of us. So there needs to be occasions to be entertained or to laugh, as a cathartic release to all the heavy stuff that’s going on. As long as it’s tied to the characters, and is character-based humor, then I’m happy to do it. And it is fun for me as well.