Newer WebKit browsers use the GPU to accelerate css-transform animations (giving your CPU a break). Check out the example on this page in the latest version of Chrome or Safari, for example:
Thanks for the resource link. I can't wait until Firefox can do this. I want to use webkit animation in my website, but for now they would only work in Safari and Chrome.
When I see what Flash does to my CPU on OS X I somehow doubt that it is more efficient.
Of course, you're not comparing fair examples of SWF vs. jQuery. I guess it's ok to ignore the obvious advantages of Flash if you can bash a full features app or animation compared to the Google Wave error page.
For me, on Mac OS X, flash is much more inefficient than JQuery animation, especially in Safari and Firefox.
What's good about using JavaScript and known libraries is that you can just write a userscript to reduce the framerate. With Flash, it would be all or nothing.
No spikes here...
0-3% in IE 8
Windows 7 64bit
Core 2 Duo E6420 @ 2.14 GHz