I don't know but Wal-Mart and Home Depot have tried muscling in on small shops multiple times and failed..meaning, opening mom-and-pop size stores. That doesn't mean Amazon will fail, just mentioning that very few people are aware that this is something the retail giants have been trying to do for some time.
The thing about Amazon is that every company who should be their competitor (Barnes & Noble, Borders, Wal-Mart) constantly botches it. They have the money to fend off Amazon. I guess that's what happens when bloated, dumb corporations get real, nimble competition.
It would be like if Amazon decided to take on Comcast selling cable TV. Comcast is huge, wealthy and established, but, and I don't think I would like this, but my money would be on Amazon because Comcast is rich but dumb.