Gee, if I was the Pentagon, I would be quietly pre-positioning as much equipment as possible in the region, and then some more. I'd bet the build up is in progress.
I agree that the equipment has been moving for quite some time and that might knock a bit off the lead-time. But it still takes time to "mate" the troops with their equipment once it arrives in theater. Then you need to exercize the men with their new equipment at every level from squad on up to division. As long as the bulk of the troops are based beyond the range of Saddam's long-range weapons systems they should be OK.
BTW, I would look for more battles like the one at Khafji where a few US Marine forward observers together with TacAir were able to destroy 1 armored brigade and severly maul a second.