But since we ARE dealing with a JavaScript and CSS3 world....
I'm really impressed with what's being done here and the possibilities that it will bring forth:
http://radiapp.com/ (this looks very promising)
http://www.greensock.com/gsap-js/
http://www.greensock.com/css3/
http://www.greensock.com/js/speed.html
The performance is so good! Check out the Mountain Dew site to see it in action: http://mountaindew.com/
(You can tell the developers who worked on the site used to be Flash Developers; it has that sort of polished flair.)
Also this: http://www.createjs.com/#!/CreateJS
And a bit of self promotion, built for the above: https://github.com/damassi/Backbone.Create