It's decent news, but people shouldn't expect the price to react on this -- merchant adoption is no longer a price driver. I am not an Amazon user at all, but there is no way anyone can deny their large market share and dominance. At the end of the day, even though they might be accepting Bitcoin, everything will get dumped on the market by their third party payment processor. Only when merchants are going to hold a certain percentage of their Bitcoin sales, the Bitcoin price might end up reacting positively.
I disagree. Merchant adoption is a pretty big price driver when it comes to big merchants such as Amazon, which is the most popular online retailer in the west. The actual fact that they accept Bitcoin is not in and of itself a good cause for Bitcoin value to go up, since as you said, they would most likely be converting the bitcoin as soon as they get it, but the fact that it can become an option increases the popularity of the Bitcoin name which may interest more people and inherently give more value to the currency, since the general demand for it would go up. The actual price delta is arguable, but the effect would be very real regardless simply because of the promotion of its existence.
