What is HTML5?
You have probably seen the term “HTML5” if you have read any of the recent articles about Apple and Flash. HTML5 is a new web page coding standard in advanced stages of development. Among other goals, it aims to reduce the need for proprietary plug-ins and add-ons (Flash, Silverlight, Java, etc.).
HTML4 came out more than a dozen years ago, when the web was just a toddler, and it is in serious need of spiffing up. HTML5 introduces new elements and attributes, including <nav> for navigation and <footer> for the bottom of a page. The elements <audio> and <video> will provide additional media functionality. Some old elements, including <font> and <center>, are being dropped in favor of cascading style sheets (CSS). In addition, HTML5 specifies new application programming interfaces (APIs) for drawing, offline storage of data, document editing, and drag-and-drop functionality.
 Before: HTML4 |
 After: HTML5 |
| Image source: HTML5 Doctor |
Development began in 2004 and the official specs should becomplete later this year. If I understand correctly, HTML5 is supposed to be more or less ready for prime time at some point in 2012. Some developers have already begun to use HTML5, but not much material is available. Nearly all of the books on the subject are only available for pre-order. One clear bits of content I found is this video by Google’s Brad Neuberg:
I’m not sure how something that is unavailable for at least a year can replace Flash on iPads and iPhones today, but I promised myself I wasn’t going to get into that …
Additional resources
- Wikipedia article
- Working Demos and Examples – by Remy Sharp
- Dive Into HTML5 – online book from O’Reilly
- Cheat Sheet – PDF from Smashing Magazine
- A Preview of HTML5 – by Lachlan Hunt
- How to use it right now – HTML5 Doctor
NspireD2: Learning Technology in Higher Ed. 
Nice.. Very Simple..
Read this from InfoWorld (the title is misleading): Google official reaffirms HTML5 readiness
and this from the New York Post – Apple may face antitrust scrutiny from FTC, Justice
I am not sure what you mean by HTML5 not being ready yet. It is supported on Chrome, Firefox, Opera, and Safari. As for replacing flash on the iPad today, have you seen: http://www.apple.com/ipad/ready-for-ipad/
As for a book on HTML5, http://books.alistapart.com/ would be my recommendation. The first chapter at: http://www.alistapart.com/articles/a-brief-history-of-markup/ , and yes it is a pre-order, but expect it to ship soon.