Jason, how's the FCK and/or Xinha progress coming? Nice work on getting Tiny MCE up and running. Could you commit the stuff to date in case someone wants to peek at the code in order to lend a hand. I'd like to get this out pronto!
Ok, got FCK's latest File and Image Manager plugins to work somewhat -- though it is not working with relative paths still (e.g. if you use a path relative to the site root and the site is not in the document root, images don't show up in the wysiwyg; plus it inserts full paths when selecting images/files from a directory). I'm thinking if we can integrate the standalone HTMLArea ImageManager into TinyMCE, FCK, and Xihna, that might be the best next step. I included the standalone version in my branch (under /manager/media/imagemanager) for anyone to experiment with.
Xihna looks great, but I haven't gotten the plugins working yet, especially the ImageManager; it's using some new backend.php stuff instead of different URLs for each action and these requests aren't working currently. I've removed the ability to select Xihna for now.
Working on checking in my branch...should be in within the hour.