Hey that's the one I went to. I preordered mine but stood in line for 20 minutes anyway not realizing that preorders didn't have to stand in that line. Haha. And yes, they did have a lot! I saw their stack of tickets. It was huge.
Why would they cater to people who preorder? Preordering only costs $5. Plenty of people would pay the $5 to get 50% off of a game regardless of whether or not they want SSBB.
To add to that, Walmart's one of the few places remaining that will take back an item without a receipt. Let's not kill that policy since I'm sure there will be many times in the future when we will legitimately need it.