Google Chrome for Mac extension support previously was disabled by default, but now extension support is active and bookmark synchronization has been added to the Google Chrome developer's build for Mac OS X.
In addition to extension and bookmark sync support, Google added for Macs 'pin tab' as a context menu item, and included a 'learn more' link on the crash page. With the latest developer's build, being version 4.0.288.1, available for Windows, Linux and Mac OS X.
However, bookmark sync still in-the-works is saddled with some flaws: a known bug related to the sync process will crash the browser when you add a new bookmark folder. Another, prevented HTML5 audio and video content from not loading, and the other stops content scripts from running twice on some occasions, notably in the Windows version.
Switching to the developer's build from the beta version, Mac users will need to manually download and install it, as the automatic upgrade path from within the Chrome beta is a different development channel.