This information was very helpful.. thank you! It looks like they did something similar to what I'm working on here. I'm warm to your idea of only supporting the window.crypto.getRandomValues browsers for the release version of Coinpunk, or at least warning users that they should upgrade their web browsers.

I wanted to ask you what your thoughts were on my skipping Arcfour (RC4) for window.crypto.getRandomValues. The blockchain.info implementation appears to still use the RC4 code (it uses window.crypto.getRandomValues for the seeding of RC4), but I didn't see why it was necessary here if I can just always get a nice random number from the newer browsers. Is this what you meant by mainlining?

Cheers! And thanks again.