"Centrino" is not a processor (CPU). It is an Intel 'standard' for laptops. To achieve the standard (and the marketing badge) a laptop must include an Intel Pentium M processor; an Intel 855 chipset; and certain Intel wireless networking hardware (options).

The Pentium M processor (something between a P3 and P4 with some saucy bits that make it very good and very efficient) is available outside of the Centrino standard - even for desktop PCs. There are plenty of good laptops that include a Pentium M but are not Centrinos.

The new Intel "Core" processor is a development of, and the successor to, the Pentium M.

There is a new Intel standard for laptops, the "Centrino Duo". It includes the Core Duo processor; the Intel 945 Express chipset and the Intel PRO/Wireless 3945ABG Network Connection.