Linux apps
You don't need to buy Linux apps at Wal-Mart. When you get a Linux system, you get access to all the apps you need for free. There are roughly 1500 discrete software packages in the Debian default apt archives alone, free of charge, an installation command away.
As for skills of shoppers . . . keep in mind that there are GUI front-ends for most Linux software management systems, and any Linux version you can buy at Wal-Mart will be one that includes such a GUI front-end. Point and click, just like Windows, except now you can use the mouse to install software without having to take a separate trip to the store to buy it first.
Games . . . well, that's its own bag of marbles. You always have to check the installation requirements for any mainstream computer game, and if it only says Windows in the list of OSes it supports, you shouldn't blame anyone else if you buy it for a Linux system and can't get it to work. On the other hand, there are a number of free games that do run on Linux, and commercial games that run on both Linux and Windows. Neverwinter Nights is a good example.
