I'm not sure how much you are willing to spend but check out the Jamis Supernova. 18.5 pound cyclocross bike with sram rival gear. It would make a decent racer with some narrow street tires. It also has eyelets so adding a rack for commuting wouldn't be a problem.
http://www.jamisbikes.com/usa/bikes/...supernova.html
There is also the Nova Pro that is a little less money.
http://www.jamisbikes.com/usa/bikes/...08novapro.html