They are introducing a box for video streaming. Details here.
Here's the money quote from the Bloomberg piece I linked above...
"The device will plug into TVs and give users access to Amazon’s expanding video offerings. Those include its à la carte Video on Demand store, which features newer films and TV shows, and its Instant Video service, which is free for subscribers to the Amazon Prime two-day shipping package. The Amazon set-top box will compete with similar products, such as the Roku, Apple TV, and the Boxee Cloud DVR, along with more versatile devices such as the Playstation 3 and the Xbox. An Amazon spokesperson declined to comment."
The spokesperson was too busy rubbing his hands and cackling with glee. "Bwaa-ha-ha-ha-ha-haa."