i think a cyclocross bike for commuting is a great choice. the geometry is usually more comfortable than performance road bikes. there's good clearance for fenders. i love my canti brakes (Paul). plus you want some forgiveness with the streets in my city. absolutely the worst this side of Baja.
the only downside, of my cx bike, is the lack of braze ons. i don't have water bottle cages, or fender holes. i just bought some SKS fenders myself, but i'm had a bit of trouble mounting them. i'm going to give it another shot tonight. they're not as easy fitting as i expected.