NetworkWorld has published an article about how HTML5 will change the web, you can read it over here.
HTML5 will change many aspects of life on the Web. It will not displace Flash or Shockwave: One glance at the games on Miniclip.com, such as Jet Ski Racer, shows how much ground the HTML5 committee must cover. But HTML5 will still remake the Web and enable basic Websites to do much more -- from tracking our location to storing more of our data in the cloud. HTML5 tags will displace plug-ins for simpler jobs, at least some of the time, and it will open up advanced capabilities to a larger audience. It might even make the Web more secure, more efficient, and more adaptable.
To see where this new standard may take us, I collected the opinions from a number of developers, programmers, and designers. Here is an unordered list of ways that the Web may change as HTML5 is gradually adopted and standardized.