I believe Amazon will hop on, but fiat will be the main thing anyway, especially in retail. We might get a price bump at start, but not much after that
I think the trend is probably that they will partially accept bitcoin as a new method of payment in the years to come as Bitcoin will be recognized as a legitimate asset.
Despite the Bitcoin being recognized by Paypal and also integrated as one of their payment methods is too early to decide Bitcoin to be used as a legitimate asset because this was one of the reasons why some government and institutions don't want to support or legalize Bitcoin but Paypal integration of Bitcoin have already make 96% of all online shops to acknowledge Bitcoin.