It looks like the Chrome team has finally re-enabled extensions on Mac again (hat-tip to MG Siegler) in the latest dev channel build. You can’t update from the “About Google Chrome” screen yet, but you can grab the latest build and install it directly.
Even better, they are now allowing Mac users to install extensions directly from extension pages (warning: shameless self-promotion link).
Extensions are working well. They’ve turned on the browser action menus, so the various extensions that I’ve installed all work properly.
Bookmark sync is enabled as well, but I haven’t seen where the bookmarks are supposed to show up in Google Docs.
I’ve really missed having extensions for this last month; getting them back made my day!