I stand corrected; the "alpha" I referred to is now the Dev Channel, which is updated (about) once weekly. According to one Chrome developer from the comments of the last post, this build possibly gets some quality assurance before it is released through the channel. On Mac OS, you can download the DMG, and you can get the latest Dev Channel release by doing Chrome->About Chrome->Update, as seen here.
Personally, I think I prefer to stay on the bleeding edge with the latest nightly build, but you can possibly do this with the "Beta Channel" as well, so oh well, looks like me script is probably duplicated functionality. I'm still using it, and it looks like the nightlies are ahead of the Dev Channel at this point at least in one really noticeable regard: the flash plugin appears to be enabled by default on Chromium builds, while Chrome requires being called with the "--enable-plugins" command-line option, as in:
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --enable-plugins
On either build, Flash movies don't quite work right in that clicking buttons play, pause, or any other button in the Flash embed is a matter of weird double-click voodoo that may or may not work. But youtube clips mostly autoplay and you watch them to completion, so as long as you don't need to reliably pause them, you'll be okay for now. I'm sure the devs will be fixing these Flash issues really soon. I wouldn't be surprised if we hear of Chrome as officially released for Mac OS and Linux within the next few months, maybe in time for the Windows 7 launch?