I was in a somewhat similar situation to the OP in that I had been riding a 2000 Lemond Buenos Aires, which is a Reynolds 853 steel frame that I thought I loved and thought I had no reason to change. As I started riding again I found that it needs some parts and work done to it, so I started looking for a new bike. I bought a new carbon bike (GT Attack, a Performance Bicycle exclusive most similar to the GT Carbon Elite best I can gather). The difference in bikes is significant, the GT Carbon much more comfortable and a comparative pleasure to ride.

I guess my point is that you may be happy with your Bianchi, but then again you may not know what you're missing. May be worth a trip to a LBS or two to check out some of their new offerings.
(btw: Some of the Aluminum bikes I test rode were excellent as well)