They say that, but their track record is terrible in this respect

http://tensquirrel.blogspot.com/2010/04/blog-post.html

Your link seems spammy but your comment here isn’t far off — semi-transparent PNG support was promised for IE4 but delivered in IE7, IIRC.

So is this a strangely delayed slap at Theora, or an early shutdown on Google's VP8?

Since they do that annoying corporate thing of not naming the competitor I don't really know what to think.

edit: I've been wondering why Flash was getting slammed by both Apple and Microsoft in posts that pit Flash against H.264, which Flash supports with hardware acceleration. Does this mean Apple and Microsoft know, or believe, that Flash will soon support VP8?

It's an attack on Firefox.

By ensuring H264 is the dominant video codec they shut Firefox out of the competition, because Firefox cannot implement a non-free video codec.

Theoretically Firefox can comment a flag in source code which use ffmpeg to render video, just like what Chromium did. The official binary doesn't support H.264, but tons of thirdparty build would.

Firefox is free to hand H.264 content to Windows' media framework for display, just like IE will.