Question: I know a fair amount about the current javascript engines. What techniques have arisen in the intervening time? Please provide links to freely available information.

edit:

To clarify, I'm looking for new techniques that are being implemented or have recently been thought up for improving javascript execution speed.

Answer: 
I think most of your question is answered here: [What optimizations do modern JavaScript engines perform?](https://stackoverflow.com/questions/2055981/what-optimizations-do-modern-javascript-engines-perform/2056026#2056026)
They [use the GPU](http://blogs.nvidia.com/ntersect/2010/09/next-killer-app-for-gpus-internet-explorer-9-beta-launch.html).