Upgrading to 12-29t instead of the regular 11-25t or even 11-27t is the new Campagnolo Cassette. While many of us want to make our bikes lighter, you can do this by running a compact 50-34t crankset and have the gearing the same as a 53, 42, 30t triple crankset. Coming this month is the Record and Super Record versions, and will fit with standard Campagnolo rear derailleurs. The Chorus Cassette will release in February 2010.
Source: Bike Radar