I tried taking the latest from the development HEAD, I updated all the js files, TinyMCE files, and I think there were like 4 php files however I found while it did load, it broke all my TinyMCE integration plugins (like my gallery2 plugin). It also blew out the posting page so the entry windows in TinyMCE was like 2000 pixels across.
I’ve used tinymce on other applications and on wordpress, and I’d say based on comparison it’s been heavily modded. Of course, anyone could have surmised that by the fact that tinymce seems to work well on other applications, while on WP it’s a hazard and a nightmare.
What this means is probably not.
You will be better to wait a little for a new version of WP the latest TinyMCE 2.0.5 is included and it does include a handy spellcheck function and a few bug fixes.
Dont think it’ll be too long before a new WP is released
In case you are interested, I got 2.0.5 working and have the hacked files available on my site:
http://www.gochnauer.org/index.php/2006/04/29/wordpress-tinymce-patch-205/
