I agree with your post. However, I would like to add one key point that everybody seems to be missing: while Google is concentrating on "The Web" as the sole source of content for consumption (GoogleTV, I'm looking squarely at you!), Apple seems more preoccupied with the inter-working of various media devices for this same purpose. In a very true sense, iOS devices form a rich ecosystem that encompasses *much* more than the Web. Tablets, television sets, HD movies, personal computers, content streaming, DVDs, etc. are all treated mostly equally in this ecosystem.
Now, the key point is that, outside the World Wide Web, the main codec for digital video used--and the de facto standard--is H.264. There is no question about this. Thousands of products, devices and applications alike, support this standard, which enriches and simplifies the experience of streaming and transferring video between them. More importantly, it opens it to any manufacturer of devices and to all creators of content, equally.
But Google makes no money outside the Web. Their core business is advertising within the World Wide Web. Therefore, it is in their most pressing interest to disrupt these external ecosystems, and promote the Web as the centralized point of access to content, while simultaneously segregating it from outside access (come on, do you think a name like "WebM" suggests it's focus on any other source?).
Make no mistake: this is purely a move against Apple. It is no coincidence that they chose to keep support for Flash--the single technology disavowed by Steve Jobs in iOS. By removing H.264 from their browser and promoting technologies not readily supported outside the Web, they are attempting to force content producers to support their "Die Web ist Alles" model with the expectation that Apple users will come back to use "their" Web, and thus extend their advertising reign and cast Apple's ecosystem to irrelevancy in one single master stroke.
That all this is done under the guise of "open" and "free" is not only disingenuous, but downright malicious. Google fans should think carefully about their allegiances, despite Apple's intentions and motivations.