It is way too soon to start thinking about HTML 5, and the main reason for this is compatibility. As a web developer I dedicate a lot of my time in ensuring that my applications run and look the same on every browser. Unfortunately I see how this task takes more and more time with every new browser release, every new specification.
I don't think that it would be a wise move to start using HTML 5 anytime soon before 2012 (when it is said the specification to be finished).
And anyway, with the rise of online video and the widespread flash support why risk it.
Of course, in the long term it would be better to have it all in the browser and I am looking forward to it, but it is just too soon now.
Manuel Lemos - 2009-07-06 22:47:07 - In reply to message 1 from Martin Angelov
You should use HTML 5 only if your application needs its new features.
The main 5 browsers already support part of HTML 5 features. If you need a feature that is not supported by one of the browsers, you may resort to existing emulation libraries that implement missing features using Flash, Silverlight, Java, VML, SVG, or whatever is available on each browser.