Yes, and the 2.16GHz is not a single processor, it is a dual-core procossor, essentially two processors on the same chip. With the more modern (faster) memory bus and the capability to provide much the same performance as a desktop while running on battery power (for laptops), this newer chip family is just the beginning from Intel, and will quickly replace the last-generation P4, which it already out-performs.
The P4 family seems to have reached its limit, the CoreDuo is just getting started.
This might look like some kind of advertisement, but the CoreDuo (and more newer-generation chips) will quickly go in all Macs
You can ask the same question of Dell, HP, and etc, why they are also going with the CoreDuo processors. Raw numbers don't tell you everything.