The real reason Apple and Microsoft are embracing 'HTML5'
crisp.tweakblogs.net
crisp.tweakblogs.net
They are adopting HTML5 for video because video is becoming more and more essential part of the web and an open standard for it makes the browsers of both companies independent of any particular plugin. No sane company wants to be dependent on others.
As for them choosing h.264 - that's simple too - h.264 is open standard (as in, no single company or other entity has the ability to change it at some random point in some random way) and is widely used already (i.e. there is a lot of software and hardware support). On top of that the patent situation with h.264 is much clearer and safer (e.g. given h.264's huge use, the longer no submarine patents surface, the higher the likelihood that there aren't any).
edit: fixed typos
Who said there's a deep conspiracy theory? Saying "they aren't being entirely open with their motives" is an observation that is almost always true of almost all businesses.
This is a classic conflict of interest. It's like finding out that your doctor who is telling you that you really need to remove a kidney has a lucrative side business selling kidneys.
This is really all so ridiculous, though. The video thing is a giant red herring -- the truth is that Flash as a video container is almost always used to thinly serve up h.264 these days. Yes, the stream should be decoupled from the player. No doubt.
Yet that blanket idea about video is used to mask the incredible gap that HTML5 currently has on mobile devices.
There's no reason to believe that H.264 is any more of a threat than MP3 was.
The MP3 format was used because the patent wasn't enforced. As soon as it was and people found out the terms of license (per file, per encoder, and per decoder) the AAC license became a better alternative (only per encoder, per decoder, and high thresholds to payments).
In one regard h.264 is almost a repeat of the MP3 fiasco. Terms are good enough to make it widespread, then severely jacked up once it has market domination. From an enduser point of view. This isn't a problem, the CE company you buy gadgets from is required to pay this. Depending on the company this could be a problem. If you are a US-based company (where software patents are valid) competing against foreign companies it can be the difference of your product not selling because of a cheaper alternative.
H.264 IS open, just as all the other MPEG "technologies" are. The complete documentation for each and one of MPEG's data formats is available to anyone, free of charge, to use and to implement in whatever way they want - it's just that the end result; the H.264 video product itself, isn't free to deal with from January 1st 2016. What MPEG decides from that date and on can so far only be guessed, and for some damned reason, everyone in the "other camp" keeps making the worst possible guesses, while always having kept their mouths shut about MPEG-1 Layer-3, and MPEG-4 ASP. I call it FUD, and hypocrisy.