I'm on the road bike today as the roads are finally dry and permit it (I hope enough, at least) but am thoroughly convinced anybody who's so dogmatic as to think MTBs have no place in a commuter's stable have never really been through a real winter!

I'll say even though I believe a solid cross bike to be the epitome of the do it all bike, there are conditions I've commuted in where having less than a 2.1 tire is a huge PITA. I've yet to see even a cross bike that can accomodate that!