Google has just added links to their soon to be launched Chrome Extensions on the home page of the Mac developer builds as well as Bookmarks sync. Whilst the extensions link is not yet live, users can access and install the sample extensions for Chromium here.
To ensure the extensions work be sure to download the latest build (here) as whilst Chrome features an update checker, I did find that it took a reinstall for the extensions to work properly. Once this was completed it is as easy as selecting your extension and selecting ‘continue’ when the download appears at the bottom of the browser.
The only feature currently lacking is the ability to uninstall the extensions at a later date although this can’t be too far away if the official release is imminent.