They are equally fast, 2Ghz = 2Ghz. Exactly the same number of megahertz.
A Corvette and a Porsche travelling at 150 Mph are equally fast.
However, as in the comparison of the Porsche and Corvette - their driving characteristics in reaching that number are different.
And just in the automobile comparison, there are those who prefer the one over the other.
Since it's a PREFERENCE, and since it has been completely been beat to death, it is probably not worth discussing here over and over again.
Do a "search" and come up with your own conclusions. Keywords: "AMD" or "Intel".
EDIT: You are also asking for "speculation" as neither CPU is currently available at 2Ghz. Shortly, they will both also migrate to a .13 micron die and their characteristics will also change. I vote for "lets wait and see".