www.mycookingdiary.com by is great example of what you can do (and how to do it properly) with #HTML and #CSS today:
– A continuous user experience using AJAX to keep the user engaged. However, each "slide" has it's own URL. This means you can bookmark it, share it, etc.
– Animation – but on user action: Yes, animations can liven up a site. But it should be controllable by the user otherwise they end up being irritating. The user needs to feel he is in control of his experience of your site
– Flexible layout: the site looks great at 800px as well as 1200px
– CSS effects to enhance the visual result: #CSS3 blur is here used to bring the attention to the main content area not as a gimmick
– Keyboard navigation: a small issue for some but shows attention to detail and professionalism