Centrino is not a CPU, it's a platform which includes the CPU and Intel specific wireless technology, and probably something else that I can't remember.
The first generation Core i series (Clarkdale, socket 1156) is about 12% - 15% faster than the Core 2 Duo CPUs, clock for clock. Therefore, a i7 960 is roughly equivalent to a C2D CPU at approx. 3.6GHz.
The two additional cores in the i7 will also boost performance assuming whatever program or game you use can take advantage of more than 2 cores.
The 2nd generation Core i series (Sandy Bridge, socket 1155) is about 10% faster than Clarkdale CPUs at the same clock speed.