1366x768, the most popular resolution, is being ignored

As of January 2013, 1366x768 resolution is, by far, the most common.

http://www.w3schools.com/browsers/browsers_resolution_higher.asp

http://techcrunch.com/2012/04/11/move-over-1024x768-the-most-popular-screen-resolution-on-the-web-is-now-1366x768/

And it's being ignored.

Youtube, for instance, doesn't render their videos at 1366px horizontal. I think they should, even if it will cost Google additional resources.

What do you guys think?