They will someday, if not bitcoin then some other digital currency.
Well if they are not going to accept bitcoin because it have an unstable price then probably they are going to accept an online dollar currency.
That is going to be possible, but it is going to be better if they are going to accept bitcoins.
Because they are a well known online shopping and it is going to have big impact in the economy of bitcoin if they do accept.
I do believe its a question of time till they work with a third companie that works with bitcoin, soo amazon wouldnt be taking any issue or risk to loose money along the transactions, look to namecheap they allow you to deposit with bitcoins, and they exchange at the value of the day, soo they are risking nothing.