Centrino isn't a processor, it just means a certain combination of Intel CPU, chipset, and wireless card.
The combinations are:
Pentium M (Banias or Dothan core,) i855 chipset, Intel 2100B or 2200BG wireless
Pentium M (Dothan core,) i915 chipset, Intel 2200BG or 2915ABG wireless
Core Solo/Duo (Yonah core) or Core 2 Solo/Duo (Merom core,) i945 chipset, Intel 3945ABG or 4965AGN wireless
Core 2 Duo (Merom or first-generation Penryn core,) i945 chipset, Intel 4965AGN wireless
Core 2 Duo (Second-generation Penryn core,) GL40, GS45, GM45, GM47 or PM45 chipset, Intel 5100, 5300, 5150, or 5350 wireless
And then there's Centrino Atom for mobile internet devices...
Atom (Silverthorne core,) US11L, US15L, or US15W chipset, any wireless card
Anyway, that machine will have a Banias processor, an i855PM chipset, and an Intel wireless card of some sort. And, that wifi card is the only difference between a Centrino and a non-Centrino for most ThinkPads.