Myth 1: the video tag will replace Flash video

The format issues over graphics formats in the 90's ended up working themselves out in the end; even though there were patent concerns, everyone wound up supporting GIF, PNG, and JPEG due to market pressures (though PNG support in IE took a while to actually work correctly). It's not going to be easy, and it may take another couple of years of wrangling to get something fully settled, but it will happen.

Of note, Google, one of the biggest and most powerful proponents of web standards, the largest provider of video content on the internet, the author of the third most popular web browser, and the main financial support for the second most popular web browser, has bought On2, the company that produced the original codec that became Theora, and which has much more advanced codecs that are currently available in Flash only. Now, Google is still in the process of going through all of the regulatory hurdles of purchasing On2, and so has not yet said what they plan with it, but given that information, I think that there's a fairly sizable chance that we'll see some movement on the codec front within the next six months or so.

Myth 2: HTML5 is here, Flash is dead

This is correct. Most of the new features introduced in HTML5 (and other modern standards, such as CSS3, SVG, and the like) are not done yet, or are at a "public preview" level in terms of compatibility and completeness. Canvas has been around for a while, and is fairly well supported portably, including a compatibility mode for IE, so it's pretty much ready to use, but some other features are not.

Right now, it's time for geeks to start playing with HTML5, building tools to make authoring with HTML5 easier, pushing it to its limits to discover where they are and fix them before everything gets set in stone by backwards compatibility limitations and inertia in the standards process. If you need to deliver interactive multimedia content to a broad audience in a month, or in six months, it's not yet time to switch from Flash to HTML5.

The leading HTML5 browsers, Safari and Chrome, make up less than 20% of the desktop market.

Er, I'd consider Firefox to be a leading HTML5 browser as well, and it commands ~25% of the market.

* Moving on, the Flash Platform today provides a far more complex level of interactivity that the HTML5 digerati can imagine, including skinnable components, embeddable swfs, movieclips, native apps w/ native processes, video and microphone input, peer-to-peer communication and file transfer, the Text Layout Framework, shared whiteboarding, and multiplayer games …and that’s just the off-the-top-of-my-head stuff.*

Some of this is bogus (skinnable components? How about CSS?), and some of this stuff that belongs not in the browser itself but in a library on top of it, using lower-level functionality (shared whiteboarding, multiplayer games), and some of this represents genuine limitations that HTML5 does not address (video and microphone input).

But the excitement about HTML5 is not simply about what HTML5 itself provides. It's that standards based web development is actually moving forward again; standards that meet real needs are being written, and implemented, by browser vendors. There was a long dead period in browser development; from about Netscape 4 until the release of Firefox 1 and Safari 1, when Microsoft had so much market share it was inevitable and Microsoft had actually ceased browser development altogether, and when the standards bodies went off the deep end with crappy XHTML based standards that no one really cared about. And until around version 3 of Firefox and Safari, and the release of Chrome, they were still to small in market share to make much of a difference. But now advanced browsers, with much faster JavaScript, support for SVG and canvas and Web Fonts in an open format and, support for video and audio and more are reaching 30% market share, and it's now becoming a serious platform.

Myth 3: Canvas is great for artists

Some parts not true (all major browsers support some form of Web Fonts by now, and technologies like Cufon can convert fonts into paths that can be rendered on a canvas even without native web font support).

The tools are still not here yet, this is true. As I mentioned above, HTML5 is now at the stage for hackers and geeks to play with it, push the boundaries, and start writing those tools that will allow artists to do great things with HTML5.

Myth 4: HTML5 will solve all the problems associated with Flash

Well, this is a pretty uncontroversial statement. There are never any silver bullets, that will solve all of your problems. However, HTML5 does offer the ability to solve many of the listed problems.

1) CPU hogging – yes, Flash pushes CPUs. But so does HTML5, even with really simple apps.
4) Crashes – this one is harder to clearly refute except to say that Flash Player 10.1 is far less resource intensive than the current version because it’s meant to work on mobile devices, which is no small effort. In contrast, HTML5 is brand new and therefore untested. As people start to experiment with complex canvases, we’re going to see CPUs pushed just as much as Flash, if not more.

The advantage HTML5 provides is that browsers can compete on performance and stability; as no content is locked in to a single vendor's proprietary rendering engine, there is actually opportunity to provide something better than one Flash can provide.

2) Banner ads – HTML5 won’t kill Flash banner ads – they’ll just be done in HTML5, but now you can’t ignore them with a Flash-blocker (note to HTML5 developers – you can have the banner market. Please. Take it.)
3) Splash pages – we finally defeated Flash-based splash intros, only to see them reintroduced for HTML5

Sure, and banner ads and splash pages existed before Flash, too, and are still done with Flash today (when did anyone defeat Flash-based splash intros? I still see them all the time). Advertisers will annoy users with whatever technologies they have available; but having it all in one format that is standardized easily navigable by DOM will make it easier for the authors of ad blockers to selectively block content.

Myth 5: Adobe is afraid of HTML5
The fact: nobody is doing more to support HTML5 than Adobe (not even Apple).

Wow, this is a bold statement. Apple, Google, Mozilla, and Opera have dedicated many engineer years to implementing HTML5 in the browsers. They founded the WHATWG, the group that originally wrote the HTML5 spec (later adopted by the W3C after it realized what a failure XHTML 2 was).

Adobe pushed for SVG integration but was ultimately won over by the flexibility of Flash.

Beyond the fact that SVG is not HTML5 (yes, I realize that people use HTML5 as an umbrella term for all modern web standards), it's true, Adobe was one of the early supporters of SVG. They did a crap job of implementing SVG as a plugin, though, and ended up simply buying Macromedia with its much better Flash plugin instead, and abandoned SVG. They haven't really shown much of a commitment to SVG, HTML5, or any other modern web standards since then, though, devoting the majority of their effort to promoting Flash and Flash based platforms like Flex and Air.

So yes, Flash had many years to pull ahead. It will take some time for the browsers to catch up, and become ubiquitous enough to depend upon. It will also take some time for tool vendors to produce tools that can compete with Flash. The disadvantage of it being done in standards is that the process is a bit slower, and it can take longer to wait for the stragglers to catch up (beyond the long head start Flash got due to the implosion of the browser market and standards process). The advantage is that the browsers can compete on stability, performance, and all of those issues that Flash is notorious for not addressing; by using open standards, your content is not locked into an engine provided by one vendor only.