YouTube recently went widescreen with making the standard YouTube video size now 16:9.

YouTube changed it’s YouTube player to 960 pixels wide. Users need to make sure that they start uploading high definition videos using the MPEG4 format, MP3 audio, a video resolution of at least 480×360, and a frame rate of 24fps or higher.

So YouTube is not the first to go widescreen, they are merely keeping up with the time. Already setup boxes are starting to stream YouTube, connecting YouTube to your living room.