From the Chromium blog, one of the more impressive performance improvements I've seen yet:
Ideally every part of a user's interaction with a browser is fast, starting with loading web pages. Chrome is introducing two techniques called script streaming and code caching designed to reduce that painful waiting time spent staring at a white screen, especially on mobile devices.
They say they have more where this comes from too, and that's pretty darn exciting. Alex Russell is on the Chrome team and was on the latest episode of Shop Talk — nice timing as he talks about performance on that episode.