Major U.S. retailer Gamestop have already filled their allocation of Wii U Deluxe Edition and are no longer taking pre-orders on it for the November 18 launch.
The standard edition are also expected to run out shortly, according to a report on The Verge.
As no actual numbers are available it's hard to say whether it's a matter of extremely high demand or extremely limited supplies, but regardless it seems it will be difficult to find units post-launch in the States. And it's an indication supply will be limited across the board.