Windows Chrome users can now take advantage of a new Chrome Channel called Canary Build. This is in addition to three other Chrome channels already available for all platforms: Dev > Beta > Stable. With Canary build Google hopes to deploy faster updates for developers and early adopters to try it out before rolling it out to other channels, in other words its supposed to be on the bleeding edge of deployment of Chrome features. Think of it as Nightly Builds for Firefox, also known as Firefox MInefield.
One of biggest gripe with the other Chrome builds was that you couldnt install more than one channel at the same time, with Canary build you can run Canary and either one of the other builds. However you cannot choose Canary build as your default browser, which is not such a bad idea considering that updates and features deployed on Canary build is likely to be less sable and may be prone to crashes.