It sucks, but I'd much rather have a "non-free" codec that plays smoothly on all my devices than a "free" codec with lag issues on everything but my computer.

Try playing 1080P H264 videos on your tablet/phone without using the H264 hardware decoder and you'll know what I mean.

Decoding H265 and VP9 will likely be even more resource intensive than decoding H264 already is

And really, does the closedness of H264/H265 really matter at all for the end users? x264 seems pretty free to me, what is the difference in reality?

And a quibble about words: h.264 isn't "closed". The standard is well-understood and easily available, and there are free high-quality implementations of both sides of the codec. What you mean to say is that it is "proprietary" and that its use is subject to IP laws and licensing restrictions.

Are you sure you're not scaremongering just a bit here?

For one thing, the royalties typically don't kick in until projects have reached a significant size. Using H.264 is explicitly free up to that point for those users, even if you accept the validity of the patents etc.

Moreover, it seems unlikely that lawyers would trouble a lot of small companies anyway, at least in places like Europe. Firstly, they'd have to notice them. Secondly, they'd have to know that the use wasn't properly authorised (since bringing a groundless lawsuit in a loser-pays system can be expensive -- you don't see the equivalent of the xxAA shakedowns over here for similar reasons). Thirdly, are heavyweight industry lawyers really going to risk a legal action that could set a precedent that these patents are unenforceable, destroying their entire business model across an entire continent, just to extract a modest amount of licensing fees from a small business? If they wanted to pick that fight, I suspect the unlucky business having to defend itself would suddenly find itself with a lot of well-financed friends.

As with most software, the closedness of H.26X matters a lot more to developers than users.

So VP9 is pretty much a non-starter.

Flash is headed for irrelevance - I doubt it will make much difference at all in this format choice. What will matter a lot more is what format mobile devices are able to play.

Other than some minor annoyance of flipping to Chrome, the only real downside to browsing without Flash is that there's a surprisingly number of sites that silently fail without warning if you don't have flash installed. I'm looking at you, eBay.

I'd love to uninstall Flash, but it'd be a major pain if I had to switch over to Chrome every time I wanted to visit an MP3 blog or news site (think CNN or The Verge with their proprietary Flash video players).

EDIT: Also, last I checked, HTML5 videos on YouTube could not be played in "true" fullscreen (they'd only take over the browser window, not your entire screen). Has that changed?

Most browsers (at least Safari definitely does) do proper full screen too.

I'm not sure if the experience would be as good with Firefox as I'm not sure if they support H.264 yet. But I heard that was planned.

I'd encourage you to try it for a while - it's free and pretty quick to re-install Flash if it gets too annoying.

2) Yes, full screen works since the JS API was implemented in all browsers (albeit prefixed until recently) except for IE.

As for VP9 being a 'non-starter', nonsense. The reason Google is creating their own in-house codec is obvious, 'online' video will be used in an ever-increasing number of services in the future, services which Google wants to provide. As such Google wants their own codec so that they don't have to licence from someone else.

When you record video in your Google Glass or play/record in <insert Google product/service here>, it will use Google's own VPx codec.

And Google Glass is vapourware and YouTube/Chrome supports H.264 so not buying the whole Google will put its weight behind VP9 argument. We heard it before with VP8.

But VP9 is pretty much a non starter for any embedded device as well. Apple, LG, Microsoft, Samsung, Sony are patent licensors so they have every reason to use H.265 in their own products. So that takes cares of the majority of all of the mobile and console markets.

Then you still have the situation where even if H.265 and VP9 are supported equally everywhere why would anybody use it. H.265 will be technically superior, be built into the core OS SDKs and have far, far better tool support from content creation to editing to output.