> If there's anyone who could effectively push open standards in this area, it's the people who do the "Acid" browser tests.
Ian Hickson, the HTML5 editor and author of the email you're posting on, is from the (co-)author of Acid2 and Acid3.
I hope Apple comes around, but whatever it is they're trying to achieve by avoiding Theora (legal risk? something strategic?), they may well consider that more important than Acid4 compliance. And if Apple makes some loud and vaguely plausible argument about how Acid4 is so unfair -- they can't possibly comply -- and ignores it, then that runs the risk of making *the Acid tests* irrelevant, not Apple.
HTML5 has a similar problem -- it attempts to make a practically relevant standard (which job the W3C has completely abdicated), but that means that it can't just go around declaring reality to be other than it is. One can see this logic in the email -- it's being dropped from the spec because putting it in the spec wouldn't make a difference either way.
I think Jon's summary is overly pessimistic. This announcement doesn't change anything. The strategy for forcing Apple to bundle Theora was always to create web developer by shipping it in Firefox, and legal confidence by shipping it in Chrome.