E oficial: Amazon-Twitch acquisition: $1 billion for video game streaming site | BGR
UPDATE: Amazon has confirmed the acquisition via the following press release:

Amazon.com to Acquire Twitch

SEATTLE—August 25, 2014—Amazon.com, Inc. (NASDAQ: AMZN) today announced that it has reached an agreement to acquire Twitch Interactive, Inc., the leading live video platform for gamers. In July, more than 55 million unique visitors viewed more than 15 billion minutes of content on Twitch produced by more than 1 million broadcasters, including individual gamers, pro players, publishers, developers, media outlets, conventions and stadium-filling esports organizations.

“Broadcasting and watching gameplay is a global phenomenon and Twitch has built a platform that brings together tens of millions of people who watch billions of minutes of games each month – from The International, to breaking the world record for Mario, to gaming conferences like E3. And, amazingly, Twitch is only three years old,” said Jeff Bezos, founder and CEO of Amazon.com. “Like Twitch, we obsess over customers and like to think differently, and we look forward to learning from them and helping them move even faster to build new services for the gaming community.”

“Amazon and Twitch optimize for our customers first and are both believers in the future of gaming,” said Twitch CEO Emmett Shear. “Being part of Amazon will let us do even more for our community. We will be able to create tools and services faster than we could have independently. This change will mean great things for our community, and will let us bring Twitch to even more people around the world.”

Twitch launched in June 2011 to focus exclusively on live video for gamers. Under the terms of the agreement, which has been approved by Twitch’s shareholders, Amazon will acquire all of the outstanding shares of Twitch for approximately $970 million in cash, as adjusted for the assumption of options and other items. Subject to customary closing conditions, the acquisition is expected to close in the second half of 2014.