It is my understanding that both Intel and AMD will be releasing 64 bit processors under the names clawhammer and itanium or some cr*p like that.
Anyway, from what I've seen (and please understand that I haven't really researched this), the MHz of those chips will be dramatically smaller than the current iteration of chips, as they derive their speed through a different method than through only fast clock speeds.
If that is the case, then Apple has a very good chance of evening the gap between Intel, AMD and Apple, because the competition wouldn't be putting out 3GHz "grannies in the fast lanes," but would be putting out chips more akin to the ppc's.
At least, that's my take on what I've read so far.