I suppose the answer is yes. The most important element of the Centrino platform is the new Pentium M processor, which has a different design from the former mobile Intel processors, which makes it work more efficiently in terms of both actual productivity and power usage, even when compared to Pentium 4 M processors with a higher clock speed.
The Pentium M processor is relativley new (maybe a couple of months), so you will only find them in new models.
Note that for a notebook to carry the Centrino label, it must use (1) the Pentium M processor (not to be confused with the old Pentium 4 M) (2) the 855 chipset and (3) Intel's wireless solution.
Some laptop makers choose to use their own wireless solution, and as a result cannot call the laptops Centrino. But these would be just as good, as long as they use the Pentium M processor and the 855 chipset.