Thanks for your comments, Joe. It's not so much that I'm surprised by the concept of deprecation, it's just that the sudden killing off of Safari 5.0.x without any notice strikes me as somewhat strange, certainly compared to the other oldtimers I mentioned. Their html5test.com scores are about the same as that of Safari 5: Firefox 3.6 = 173 (but 4 = 240, and I tested the immediately preceding 3.6.28), and Opera 10.60 = 239. Seems to me that Youtube wasn't taking this particular metric as gospel, or as the only criterion for deprecation. That is, if it actually did, of which I'm not so sure any more.
That's because the situation still seems to be in flux: Safari 5.1.10 started working again with Youtube sometime after I posted the error above. No more mention of deprecation on a special splash screen, go figure. Safari 5.0.6 still displays Youtube pages text-only, but instead of mentioning the deprecation it now states 'This video is unavailable'. That seems to apply to
any video.
I'm just sayin': weird!
