This addon will save your action bar buttons (ALL of them) which can then be loaded (copied) after switching spec.
Does NOT work with addons that create their own buttons (like Macaroon), only standard WoW buttons are supported (most action bar addons use the standard buttons.)
WARNING: Copying (loading) buttons will replace any you had before that are in the same place.
Run "/nbc store" to save your buttons while in the spec you want to copy from, then run "/nbc load" after switching spec. Done!
P.S. Flyout buttons are not supported (Call Pet, Teleport, Portal, etc.)
DISCLAIMER: Use at your own risk! I'm not responsible for any button mishaps