Google one-ups DNS pre-resolution, adds predictive pre-connections to Chromium
As with most of these clever under-the-hood type changes, it's hard to describe just how much this will improve your browsing experience, but I'm going to try.
Basically, pre-connection opens an HTTP (or HTTPS) connection to a search engine before you've finished typing your query into the Chrome address bar (Omnibox). With the socket already open to Google (or Yahoo, or...) your complete search term can be quickly transmitted. Like the clever DNS pre-fetching already present in stable builds of Chrome, we're probably looking at significant speed-ups of half a second or more. Neat.
If that wasn't cool enough, the same patch includes pre-connection to 'subresources, such as images'.
If you navigate to a site that you've visited before, and your surfing history suggests you usually click through to a linked site, the speculate pre-connect code will open a socket to that site! The obvious example is searching Google Images: speculative pre-connect would open a socket to each of the search results. Thus, when you click an image, you'll again see a significant speed increase!
To test out the speculative pre-connection you'll have to grab a recent nightly build of Chromium and use the --enable-preconnect flag.