Originally Posted by Chrome Molly

I'll differ from some of the advice above...
If performance is your goal...

First tires - something nice like veloflex masters or Michelin pro 3's
Second rims, something in the 1500 gram range with fewer spokes to help deal with crosswinds
Third components, Veloce brifters (new cables included), 8 speed cassette, ultegra RD. Alternately spring for a whole 105 or veloce gruppo
Fourth, all the other weight saving stuff

Your steel frame has a nice ride. Tires and wheels are by far the biggest bang in terms of noticeable performance benefits. You're better off buying great wheels, tires, and components on a mid level steel frame instead of settling for crappy stuff on a whiz bang carbonific thingie. If you're looking for something that inspires you, consider a new saddle, bar tape, etc to change the look.