Post #49 I hope and suspect that the Macbook will go with Merom as soon as it is released, since the Merom is priced the same way as the current Yonah lineup. Apple now has to compete directly with Dell and other Winbox manufacturers, since it is using the same hardware. If Apple uses a Yonah in a Macbook and Dell offers a Merom-based laptop that's 30-40% faster for the same price or less, Apple is in trouble. So, if Apple continues to use Yonah (if Intel even continues to make it), it will have to drop the price of the Macbooks substantially, and I doubt that Apple is prepared to do that.
Look for the 1.66-1.83 (or maybe even 2) GHz Meroms in the next generation of Macbooks, since with the 20-30% speed boost over similarly-clocked Yonahs, even with a 10% drop in clock speed, they will still be faster, cooler-running and less expensive to make than the current models, will likely boost battery life and will offer 64 bit compatability.
The MBPs can all use Meroms clocked above 2 GHz for differentiation of lines, as well as their dedicated GPUs, larger (and maybe faster) HDs and more installed (and maximum) RAM.