I am sure walmart has been told to NOT sell the backlit SP's for that day, but it will be very interesting if someone manages to con them into selling a backlit sp, it is possible they might remove the backlit sp's from the shelves as well that day, and just stick out the old front lit sp's.
And for anyone thinking of buying an SP, go for the backlit, i am serious, once you get the backlit you will never ever go back to the frontlit one. I have a backlit SP, sold my frontlit on ebay as quick as possible before people realized the difference, and i would never go back. The frontlit screen doesnt look much better than the screen of a game gear. When you see the backlit screen you will NOT regret your purchase trust me, 50$ is a total ripoff on the price of the old SP, it should be like 10$ cause thats all the quality of the lighting is worth. I cannot even describe how nice the backlit SP looks, you have to see it for yourself to believe me!
If your buying the SP as a gift for some kid thats gonna destroy it, get the frontlit, cause a kid will care less about the backlit screen, as long as they have an SP they will be happy.