Our hardware acceleration is a bit different from what other browsers are doing. Like IE9 and Firefox 4, we do full hardware acceleration of all draw operations - but unlike those browsers, who only offer this acceleration on Windows Vista and Windows 7, our implementation will run on any OS with sufficient hardware support. This means we can have full hardware acceleration on Windows XP, Linux, Mac OS X and OpenGL ES 2 capable devices such as recent smart-phones and web-enabled TVs.
I opened up GPU-Z with Opera 11.5, I have an AMD 5770 and run Windows XP. In Chrome, Firefox 4 and IE9 (VirtualBox with 2/3D acceleration enabled) my site's show/hide sidebar DHTML animation hardly utilized the GPU, about 1~7% utilization tops. In Opera 11.5 the GPU was utilized between 74~81% while underclocked and it's effect was exceptionally noticeable. The Quake 3 WebGL Demo produced similar results, Firefox 4 utilized 7~17% of my underclocked GPU while Opera utilized 99% underclocked and about 75% at stock speeds. The Quake 3 WebGL demo wasn't flawless however this is the first public build though it's clear that Opera will have the lead once 11.5 is out of development. Imagine if you will in a year browsing a fully accelerated WebGL site on mobile device.