And for some reason, YouTube made sure to note that "IMAX movies are projected through two 2k resolution projectors".
Ummmm... why is YouTube doing this? I haven't a clue. Perhaps someone could enlighten me about this. Because I'm having a very hard time imagining why anyone would need to display video at 4096 x 2304 (do they even make monitors that big?).
Heck, I've seen 1080P projected onto a regular-sized movie screen, and it looked just as good as regular film. Not really sure what mainstream purpose 4K could be serving at the moment.