Just to clarify some more information and so much misinformation is out there:
– HTML5 is simply an update of HTML4. It does a few extra things, like include a video tag. It is not this be all end all code that will replace Flash and by itself is not very powerful.
– HTML5 is not compatible on most browsers right now. There are many standards issues. Please see this report for more details: http://www.longtailvideo.com/html5/.
– Flash is used for a lot of things that it was not designed for, like web banners, just because there is not other tool out there. Flash was designed for rich interaction and games not web banners. HTML5 is not going to be used for these rich interactions and games, flash will be. Maybe someday this will happen, but not in HTML5. Maybe HTML6, 7, or 8. But remember Flash will continue to evolve as well in that time.
– The power of HTML5 really comes with mobile devices, not PCs. However, with more advancements in mobile processors such as quad cores, etc. This really isnt going to matter much. The only thing really stopping Flash right now on mobile devices is Apple. However, you can put flash onto apple mobile devices – its a workaround though and not a process the average user can accomplish. Having said that, the same can be said of HTML5, the only thing stopping it from PCs right now is compatibility so as that gets better its use will grow.
So what exactly will HTML5 be used for that Flash once did?
Mobile applications. HTML5 will be used in the mobile world. Its more compatible and it’s free, which is the pure beauty of HTML5. However the main thing to point out here: HTML5 runs different on each browser right now. So its great if running on one device, like the iphone. But if running on android, iphone, and pc its really a pain to code. Flash is much better when using multiple devices. To get HTML5 to work on multiple devices I need to ‘trick’ the code for each browser which takes a lot of extra development time and adds a lot of extra code to my product.
Here are two good sources discussing this issue:
*I am sure there will be many more HTML5 posts on here as it evolves:)