If you are looking for a little more speed, for now you can go to a 700x32 hardwall slick tire. Since you are only riding on the pavement you don't need all that tread.
Never having ridden through a winter myself as this is my first year commuting, I have a question for the winter veterans. Do you change the rubber on your wheel if there is snow forcast? Do you have a rim with a studded tread ready to go, or do you have a mtn bike all studded and ready to ride?