Joannesalfa - no, 3D CSS transforms are slower and use more memory than a hardware-accelerated canvas - so we're sticking to the 2D canvas for now.
Are you serious? i tried it 3D CSS on my iPod Touch 4 , it looks faster than Canvas, even can make primtive 3D objects using CSS without webGL.
CSS3D consumes more memory, is true.
If you're trying to target mobile, for example, CSS animations are your only choice because Canvas is too slow in general.
I know we can wait HTML5 goes to be 100% in 2014, well, actually, i believe it cannot guarantee the peformance on mobile devices from 2011-2012 that support latest HTML5.
Maybe CSS is another solution for mobile devices that don't need to go appstore.