A great slideshow I came across on HTML5 and search engine optimization..enjoy
Since the advent of the first web search engines, designers and developers have struggled with issues of how to increase their placement on a search engine results page.
With the major search engines (Google, Bing, etc.) unwilling to reveal their ranking algorithms — protecting them from “black hat” search engine optimizers attempting to game the system — “white hat” search engine experts must play a constant guessing game to determine which tactics will be most effective.
The introduction of HTML5 has simplified many tasks, but adds another layer of complexity in this area.