We just got another major player. 

I don't think bitcoin has the necessary infrastructure to handle Amazon yet.  The amount of volume that Amazon does - even if bitcoin captured 0.1% of their orders, which is unlikely, it'd be a massive amount of orders.  For a player the size of Amazon to adopt bitcoin, they'd need one of two things: either a proper hedging platform so that they could hedge away the massive price fluctuations of bitcoin, or a widespread enough bitcoin adoptions that they could hold bitcoin directly and pay their suppliers with bitcoin instead of dollars.  I'd prefer option two, personally, but we're many years away from THAT widespread an adoption of bitcoin.