About a year and a half ago it was reported about Google’s view of HTML5 and to quote directly what John Muller has to say about it “our crawlers are used to not being able to parse all HTML markup,”. He also said that “HTML5 is still very much a work in progress.” But with 1 and half year passed by, same Mr. Muller has said that there is no flaw as such in the usage of HTML 5. Infect it said that HTML5 is generally cleaner code generating utility which has enhanced ability to assimilate meta formats
Our crawling and indexing systems currently don’t do anything special for HTML5, so there is no “bonus” for using HTML5 constructs, but similarly also generally no downside.
That said, most of the pages with HTML5 markup that I’ve seen tend to be very clean – with little “cruft” and unnecessary elements. While having clean markup isn’t something that our algorithms explicitly look for, we occasionally see pages that are almost unparseable. Also, clean markup makes it much easier to maintain the website, easier to add new elements like microformats, and frequently makes the pages more portable across a variety of browsers and devices. So with that in mind, there’s nothing holding you back (from a search point of view) from creating an awesome site in HTML5
Now the tone of john’s message is clear as crystal that he has no such feeling about HTML 5.At least not right now. Frankly speaking, it can even be understood that he might be suggesting it to web designers. Now with this high level assurance you are free to go to the HTML 5 route. It should not be typically mentioned that animations, movies and such visual content might be indexed by Google but might not feel grabbing much higher rankings.