Hi all. Thanks for your comments on this. I've addressed a few of the misunderstandings and concerns raised here on HN, Twitter et al over on my blog: http://daneden.me/2012/07/max-css-in-depth/
The benefits of CSS animations are plenty. Unfortunately, support is still very scarce: the Webkit team brought the animation property to the CSS3 specification. Mozilla have only very recently added support in Firefox.
however, both Microsoft and Opera have announced support in their upcoming releases.
In my opinion, CSS animation are much easier to write than Javascript animations, and don't require external libraries such as jQuery.
true, but as I've said here and on the site, the animations featured in the library are meant for interaction. I agree that until this tech evolves, games etc are better suited to Javascript animation (or even flash - or just let them stay in advanced languages and dedicated platforms!)
vihnboy - a debugger for CSS animations would be great. Luckily, the webkit inspector will tell you all the CSS properties an element carries and indicates CSS errors. However, it doesn't show you errors with associated keyframes - that would be awesome.
james33, johnyzee - the tech is pretty well supported, but indeed has a long way to go. It's in the css3 spec, which is great, and IE10 will support it. Remember - it's an extra layer of interaction, not an important feature of any website. use it subtly.