If you have a nice road bike already, I really wonder whether it makes sense to get a cyclocross or touring bike. Really, the ride on those will be quite similar to what you have now.

For $1500, you can afford to knock the sweaty socks off every bike commuting snob on this board and pay to import yourself a Gazelle. That's right, the bike that's so practical and sensible that it's all but barred from the U.S. No need to shop for a rack and panniers and all that crap; these Dutch puppies come with everything, including chainguards (something that can be a living hell to retrofit to a bike). These things were designed and marketed for a buying population that actually use bicycles for daily transportation, so you know it's going to suit all your commuting needs just fine.