CKEditor is licensed under LGPL, so you're good there. As for plugin_ckeditor. I wrote it, but I haven't given it a license yet (on my todo list). However, I will probably go with LGPL as well. It only makes sense as web2py and CKEditor are both LGPL. So you are all set with the CKEditor stuff.
Everything that I release and publish to the public, such as plugin_ckeditor, I do so with the intent to allow people to use it for their own purposes, whatever they may be, so long as they contribute changes make to my work back to the public. This is pretty much what the LGPL is for (from my understanding).
