Just thought I'd let you know.
I have WorldEdit 2.3.2 and CraftBook beta branch built successfully.
Everything works in CraftBook so far, except Toggle Areas.

After I select an area, and type /savearea cactii, it shows this:
WorldEdit..jar does not exist in plugins/.
(yes with two periods after WorldEdit)

I believe it has to do with loading the plugin within getRegionPoint() in WorldEditBridge.java for WorldEdit. That's as much as I know.

But it could be that a directory doesn't exist. I don't know. Hopefully you can figure it out. Just trying to give a head start. :)

Anyways, glad the beta branch is moreover successful.

Try the newest version.

If it's still a problem, report it here:
http://www.assembla.com/spaces/craftbook/tickets