Apple would be wise to skip the entire Nehalem generation of chips (except in desktop towers) and wait for Westmere which will implement the same technology with a smaller feature size: 32nm versus 45nm. The new chips will draw significantly less power at the same clock which will allow clock speeds to return to the values we've gotten used to.
Westmere will also bring hardware accelerated encryption so, for example, entire hard drives could be encrypted and decrypted on the fly without the user noticing.
Westmere will also bring hardware accelerated encryption so, for example, entire hard drives could be encrypted and decrypted on the fly without the user noticing.