HTML 5, what should I tell my clients?
More of my clients lately are asking me about HTML 5 and I'm trying to get a sense of what to tell them. How long until all the major browsers have standard support for it? How long until I leave HTML 4 behind and only code new projects in HTML 5? What are you telling your clients?
You've already gotten some good answers, but I'll chime in as well. I wouldn't give your client a blanket "yes" or "no" on html5. I'd take a look at what all has changed and then break it down into sections based on how well it's supported.
Nothing is stopping you from switching to the html5 DOCTYPE today. Even browsers that don't understand html5's new tags (most notably IE 6-8) will recognize <!DOCTYPE html> as a valid doctype and not switch into quirks mode. After declaring that your document is an html5 document, you're free to use (or not use) html5's new tags to your heart's content. Personally, I've started using the html5 doctype on websites -- even if I have no immediate plans to use html5's new features -- because there isn't any negative side effect, and as a bonus I don't have to try to remember the correct way to write a doctype and charset everytime I start a new page (which I have to do with html4/xhtml).
New (Layout) Tags:
Next, you have to figure out why your client is interested in using html5 in the first place. My guess is that they're interested because it sounds trendy and cutting edge. In reality, one of the biggest benefits of many new tags (such as <section>, <nav>, <footer>, <aside>, etc) is that they make your code much more readable than it would be if the page was filled with <div>s everywhere. This is a great advantage for the coder (and in the future it might help with accessibility), but right now, this change probably makes very little difference to the client.
New Features (Video and Audio):
Alternative, the client might have specific html5 features that they want their site to use. Two of the most popular are the <video> and <audio> tags. The great thing about these is that you can easily fallback to Flash, so you don't have anything to lose (as far as browser support goes) by using them.
Other popular new features are <canvas>, geolocation, and local storage (not exactly html5, but related). For these, the fallbacks (if they exist) require a lot more work on your part. If your client really wants these features, you'll need to figure out which browsers they (or their customers and site visitors) are using, and what percent of their target audience they're willing to leave behind.
That got a little long-winded; long story short, I'd tell your client this: "I'll gladly start using some html5 features immediately. Remember, though, that the specification is not finalized, and it will continue to change over the next 10 years. Around 50-60% of our clients may be using browsers that don't support some of html5's new features, so we'll need to do thorough analysis before adding certain complex features of html5."
Are they asking about specific HTML5 features or HTML5 in general? At my company we haven't said anything to the clients, but we do set the HTML5 doctype as well as using some HTML5 markup - but only markup that works in non-HTML5 compliant browsers. HTML5 doesn't necessary mean you discard older browsers, it depends on which features you implement. You can still use audio and video tags, as long as you keep a flash fallback - as an example. HTML5 form tags are poorly implemented even in bleeding edge browsers, so using them are not an option.
I suggest you read Dive Into HTML5 to see how you can work with HTML5 today, but still support non-HTML5 browsers.