All of the new Intel Core Duo and Solo CPUs are 32-bit. They don't have EM64T extensions.

Since Intel's 64bit EM64T CPUs are not backward compatible with most earlier P4 systems, it's probably a safe bet the notebook chips, when they're released, won't be, either.

If you want a 64 bit PC-compatible notebook CPU, there's still just one game in town - AMD.

Those are desktop CPUs, though, and given most companies' experiences with them, I'd give them a very wide berth.