I have a Trek 7.3 FX, which I've used for commuting for the last year or so. My commute is a bit longer than yours (17+ miles each way, depending on the exact route I take).

Fenders are essential if you intend to commute regularly. Here in the northeast, it can rain pretty much any time. You'll be much more comfortable (and cleaner) on a bike with fenders. The Trek FX has lots of clearance for fenders. I recommend Planet Bike hardcore/freddy fenders with mudflaps.

I've recently acquired a Surly Cross Check, which is probably going to supplant the FX for most things, but the FX has served me well. If my commute were shorter, I might well have kept using it.