>HTML5 isn't all that different from HTML1,2,3,or 4.
>
>You just use tags for video instead of Flash.

Well, just for that, it would worth it. Cause, I hate to have to include those Flash modules when I have to.

>Other than that, I don't see much of a difference, or why people that don't make web browsers would even care what is HTML5 and what isn't.

I see that everything has to be XML compliant. That would probably be the big change wherever it has to be applied. So, in general, if I would want to benefit of HTML5 related tags, I would need to make sure the entire page is XML compliant. As of today, are most browsers compliant with HTML5?