Even if this release is not yet targeted to production web sites, it's stable enough for it.
It may be stable but it's by no means ready, this is really unfortunate. The new icons are really ugly too I don't see why you couldn't have used the old ones these new ones aren't polished. Also the source code is really messy and was in gigantic condensed lines thanks for making it easy to read for us to help.
Also using a function to find the location of where CKeditor is installed is not recommended. I have made a PHP script that essentially gathers required JS files (for ckeditor and my own personal applications) and puts them in a single <script> tag, that way you don't have a dozen <script>'s in your code and making it very messy. So a config option for the install path would be nice, I modified the baseurl variable to do what i needed it to do but again, condensed code makes it difficult to find.
the options are not listed or well explained at all anywhere that i could find easily and there's no file upload support which is a huge disappointment
so even though FCKeditor is old and klunky it is a much better choice right now
sorry i didn't mean to just say the bad but that's where i ended up