I was surpriesd to find that when I tried to set up a new Folder Action in 10.8.2, it wasn't available; "Folder Actions Setup…" wasn't an option in the "Services" menu for any folder. Apparently, it's a pretty common problem for Mountain Lion users. Here's how I fixed it.
~/Library/Scripts/Folder Action Scripts/& drop the folder action script you want to add in there.
- Strangely, open System Preferences → Keyboard → Keyboard Shortcuts, and click the "Reset to Defaults" button.
- Scroll up to the "Files & Folders" section, and make sure that the "Folder Actions Setup…" listing is checked.
My guess is that if you were like me and had some custom keyboard shortcuts when you upgraded from 10.7.x to 10.8, it borked up the Keyboard Shortcuts upgrade, which in turn borked up the Services menu. Dumb.