Tnx for the heads up on this. YT is still having many problems with formats not playing properly. In recent months they broke the compatibility of 3D and it has become a real crap shoot trying to upload any 3D content, and how it plays or different people. Adding 4K will further complicate an already broken uploaded if attempting to use these advanced formats. If you use traditional video, even HD, it works well. I think their recent attempt to add html5 was what broke the 3D players.
For those wondering, yes, you will need special new graphics cards and processors to play any 4K content. I wonder if the new Sony 4k TVs or others will have a YT app that supports YT 4K direct? That would be the easiest way, as opposed to building a computer with 4K graphics. I'm not about to upgrade my 3D editing system for 4k. I'll leave that for the next generation of stereographers.
