I guess I'm a bit late weighing in on this but here's my two cents. I'm a licensed FFL dealer. My business is gunsmithing which requires the same license as WalMart's. I sell very few guns, mostly to friends who want something they can't find locally, I'll order it for them, I don't stock any inventory. If someone wants the standard Marlin 336, Ruger 10/22 or Remington 700, I have to tell them that they can get it cheaper from WalMart than I can get it from my wholesale distributor once I've paid the shipping. I'd go there myself if I wanted something they stock because, after shipping, my wholesale suppliers can't beat WalMart's retail. Since the buying and selling of firearms is not my primary business, WalMart doesn't hurt me a lot. But you should understand that if your local gun shop prices things higher than WalMart it is not a "rip-off", they have to pay more than WalMart up front, they have a small fortune invested in guns which may sit for years on the rack with no return on the investment, they have overhead expense with no "other departments" to defray the expense and many other reasons they simple can not compete with WalMart's prices.
The problem is, yes it does put your local gun shop out of business and before you know it, WalMart will be your only option, both for purchases and for employment.