The madone 4.5 frame will make for an excellent commuter. '09 or '10 models?

09 2.3 has carbon stays, you can probably get a decent deal on it now that the '10 model is out and very different. Parts spec isn't as good at '10 model.

10 2.3 is all aluminum, but upgraded parts spec (full 105 group). Has eyelets on fork and rear dropouts, plus there's a single water bottle type rivnut on the back of the seatpost about 7" up from the bottom bracket which appears to be a forward fender mount. Looks like it could be made into a halfway decent commuter.

4.5 would be a *****in' ride, but would be compromised as a dedicated commuter. No rack or fender eyelets, although there are certainly viable workarounds.

With either bike, if it will be your main commuter, consider a spare set of wheels right off the bat, 28 or 32h. Unless you're planning to upgrade the wheels anyway. Also, maybe think of replacing the tires with 25c Hard Case tires at time of purchase--see if you can work out a deal for them. If you're not going with a floor model and the dealer will have to order one in your size, you may have a choice regarding triple or compact double on either bike.