I finally got my preorder/layaway at Wal-Mart today. Tried two other Wal-Marts in Cary and Morrisville, NC. One was sold out and the other had no clue about the Wii U layaway deal. The store supervisor said that they weren't getting any for preorders.
Then I called the Wal-Mart in Raleigh Brier Creek and they actually knew what I was talking about. They had flyers in the electronics and layaway department.
I've been checking my local Target for the past 3 days for preorder cards but there weren't any signs that they had gotten any. Hope the Wal-Mart layaway preorders go through!