Chrome Beta for Mac will run on OS X 10.5 or later only, which means you must have Leopard or Snow Leopard installed.
For Linux users Debian, Ubuntu, Fedora and openSUSE are supported.
Themes, extensions and various plug-ins might not play well with these betas, but if you get them to work, let us know. Below are the download links for Chrome Beta:
Download Google Chrome Beta for Mac OS X
Download Google Chrome Beta for Linux
Update: Themes work fine with Google Chrome Beta on Mac and Linux but currently extensions only work with Chrome Beta for Linux. Here’s a video posted on the official Google Mac blog: