Because HTML5 is still a work in progress and not due to completely roll out until the latter part of 2011, there is no urgency to redesign a Web site using the new iteration of the language. Only a handful of major brands, including Mozilla Firefox and Google Chrome, currently support HTML5 elements. Those companies' browsers are only a small fraction of the browsing populations. Microsoft's Internet Explorer is the most widely used browser and currently has the least amount of support for HTML5.
Browser Support for HTML5
The browser most used by the general population is Microsoft's Internet Explorer. Microsoft is one of the companies slow to implement standards other than its own. Until Microsoft fully implements HTML5, developers will have to continue supporting HTML4 on their Web sites or risk frustrating users who don't use browsers that have HTML5 support.
In addition to lack of consistent browser support, one of the major speed bumps to widespread HTML5 adoption is the inability to agree on which multimedia formats to support. To make multimedia accessible across all browsers, there needs to be a consensus. Getting power players like Apple and Microsoft to agree on that formatting will not be easy or quick.
Until those particular standards are set, designers will not know in which formats to encode multimedia elements to comply with HTML5. Guessing and encoding your multimedia with the wrong format will waste countless hours. In the case of multimedia, it is better to wait and encode everything once in the correct format.
To Redesign or not to Redesign
Since most browsers only partially support HTML5 elements at the moment, it doesn't make sense to fully redesign a Web site using the new version of the language. However, when HTML5 does become the recommended standard, your business should be one of the first to adopt if your aim is to keep up with advances in technology.
If your business does its Web design in-house, it is a good idea to allow your designer to familiarize himself or herself with the changes in HTML5. You might want to redesign your Web site in HTML5 but hold off on launching it until you are comfortable with the level of support from your audience's browsers, or you may choose to roll out HTML5 updates as they become supported. CanIUse.com will be a valuable resource for the latter choice.
Preparing for HTML5
To stay informed about HTML5 developments, there are several online resources to reference. Mark Pilgrim's "Dive Into HTML5" is an unofficial crash course into what's new and available using the new language. For the savvy designer, the WC3 has a working document of differences between HTML4 and HTMl5. Tripwire Magazine has a list of over 25 useful HTML5 resources for a more in-depth look at the language. Familiarizing yourself with how this language can affect and enhance your Web presence will help you and your business stay on the forefront of Web design.