Explanation to follow... basically, this is a playlist of test videos meant to explore the issues surrounding HQ rendering on YouTube, especially when the video trying to get HQ rendering happens to be in a 16:9 aspect ratio.
I'll try to explain more if I learn more.
Not much more is known just yet... I might pull out some individual videos here to discuss why they were rendered and what they were meant to explore.
Suffice it to say for now that YouTube seems to have come up with a decision algorithm for NQ vs. HQ that is essentially looking for artifacts (or at least characteristics in video that it assumes to be artifacts). It's now been confirmed that at least the intent of recent, unpopular changes in transcoding practices will tend to favor those videos shot in the most traditional -- read, locked-off, or very stable panning and other shooting styles that tend to result in very low amounts of artifacting under h.264 encoding. At least that's what I understand so far. Hopefully there will be a little more dialogue to get a better understanding of how this works and, more importantly, what it means for those who prefer HQ rendering over NQ or HD, and wish to tailor their rendering practices to get it reliably. At this point I'd say the main things to take away are that you shoot very conservative, use only minimal amounts of blur in post processing, and (possibly) render in the best resolution you can manage that is less than 720px high.
That might mean 1024 x 576 or 768 x 432. But don't hold me to that until I revise this a bit more. Note: if the previous sentence about "But don't hold me to that" is still here, I haven't revised this past the first public draft.
Feel free to ask questions in the comments.