Aloha Editor is a WYSIWYG editor that runs directly in a web page. We’ve written a plugin to Aloha that goes with the Firefox addon. This enables a copied image to be pasted with an automatically generated caption with image credit and license information.
You need the firefox addon to be installed (version 0.3.0 or later). Notice also the difference between the addon “Paste image” context menu command and the regular “Paste”.