Streaming content is as popular as ever and the market is crowded with streaming device options from Roku, to Amazon's Fire TV, Apple TV, Chromecast, Android TV. You get the picture. On Thursday, Comcast announced the Xfinity Flex streaming box. It's powered by the same OS that runs on its Xfinity cable DVR boxes. Apple is set to announce its own video streaming service very soon and Xfinity wants to make sure that folks hear about the Flex before that happens. It's a streaming box for those Xfinity Internet customers who don't have set-top TV boxes. Unsurprisingly, being an Xfinity...