Apple pushed forward HTML5 (mostly) because their products have poor flash support. flash is faster on windows platform, even on same hardware. Adobe refuses to give apple some control over the format and it's a well-known war (ipods and iphones have no flash because apple wants to implement a custom-version not to allow flash game and app development beyond their control).
Google just wants to be on the front row and implement some self-suited code on the new format. Note that this is normal and a good thing. There's always peace when we agree on something, but when opinions differ doesn't mean war: that's how we evolve

can't wait for micro$oft approach to this. I bet they will try to push Silverlight all the way until the format is dead, and then when everybody is developing html6, they will finally merge everything in I.E. 10.0 or something like that...