Amazon.com canceled all of the orders for the set.
Nintendo canceled all production of the set (retarded rumor).
Amazon.com removed the page because third-party merchants was pre-listing their pre-ordered copy for as much as $250!
I pre-ordered the limited edition set on Amazon.com, and I can report that the company didn't cancel my order... so you can rule out reasons number 1 and 2. Reason number 3 is the most logical explanation for the disappearance of the item's page.