Given the way Wal-Mart does business, I wouldn't be surprised if they're buying this at a discount from publishers and offering some sort of kickbacks \. Whatever the case, I applaud it. I hope they're making a compelling case for lower first-run retail prices.
EDIT: Scratch that... I wouldn't be surprised if they're bullying publishers into supplying these games at a discount.
I wouldn't think so, games aren't like certain brands and supermarket items and shit, games can be sold ANYWHERE.
The pull with Wal-Mart is that "we will get your item out to the people because we have a lot of stores with a lot of people coming through... this'll cost you though."
Games though, people think BB, FS, EB, etc when they think video games. Wal Mart's coming up there and they need to get in on this "videotape pac man" while they can. They wouldn't be doing the publishers any favours by buying it at a lower price, this is just WM's way of getting people IN, and while you're there they're hoping you'll fall for their low low prices.