Side-by-side versions of different browsers are critical for us webdevs. On some browsers, it's because multi-year-old versions are still prevalent (luckily, you can start ignoring them). In the case of Chrome, nearly all users are up-to-date with the very latest Stable release. Being the forward thinking chap/gal you are you want to try out new stuff like WebGL that's only available in the Dev channel. But you don't want to mistakenly build something that uses features users don't have yet. What to do? Side-by-side installs, a.k.a. the Canary channel! Now you can test with Stable while plotting world domination on Dev. Awesome.
This new version will auto-update with the new hotness at roughly the same rate as today's Dev channel but will allow you to install and run it alongside a Stable channel version of Chrome. This new channel is Windows-only for now, but you have VMs for testing anyway, right? Happy testing!