However, I'd suggest there's a bit more joined up thinking going on at Google than this narrative suggests. Spending $130 million to create a royalty free contender for web video and convincing world plus dog to support it seems above the pay grade of any individual unit.
It wouldn't surprise me if this advance announcement was intended to coincide with Youtube finishing their WebM encoding and Youtube in some way promoting their HTML5 interface and WebM along with it. Not in a brutal, shut of H.264 completely way, but I can see them dropping it from the HTML5 stuff while still serving it via Flash and clients such as iOS and Android, and possibly making the HTML5 stuff desirable in some small way. But his main point stands, that sticking it to Apple doesn't really cut it as a plausible theory.