Lets be a bit clear here, Apple's choice of supporting H.264 didn't force (many) people to change their encoding format. H.264 has long been the primary choice for video (outside of the Microsoft formats).

A lot of people are saying "boo Apple" for choosing H.264 for their iOS devices. This is despite the fact that it really the only viable choice for their users. VP8 was proprietary up until May of last year and Theora is really not comprable with respect to bandwidth and quality. There was not a viable open format until WebM and at this point H.264 is deeply entrenched.

Personally as long as the W3C doesn't declare a format for the video tag (like images) I'm okay with Google's move. I think its going to greatly slow adoption of the video tag however. At this point most content providers are going to stick with Flash online for their video players so they can then provide the same (unwrapped) video for their users on other devices. When video content providers are to enocode once in H.264 and use a flash player or encode twice to partially support a now crippled native video tag, I think they are going to stick with one codec, and use flash. Google's choice may strengthen WebM's position in the long term but its weakening native video in the short.