I expect Amazon will stay the hell away from that market. Note that they haven't even gone after cars, which are a much easier thing to sell.
Homes are a mess: novice buyers and sellers, complicated laws, tricky financial deals, and a "product" that is complex, unique, and can have many hidden flaws. Real estate agents frequently get sued when things go wrong [1] [2]. The last thing Amazon needs is to get in the middle of that.
Buy a Nissan Versa Note: http://www.amazon.com/gp/feature.html?docId=1001359341
I really wanted to put my affiliate ID on that link ;)