TinyMCE 3.0 is fast approaching release and has a lot of improvements (most under the hood). The API has changed a lot too and none of the WordPress customizations is working properly. However with help from TinyMCE's team, we should be able to make it a perfect match for WordPress.
This patch includes the standard configuration plus the "media" plugin necessary for supporting embedded video and the "safari" plugin. The wpautop php function has to be changed a bit too for this to work well. The tiny_mce_gzip.php is disabled - it needs changing but also it's much easier to test js files when they're not concatenated. I've managed to get the tabs working (not in IE yet), but good enough for testing.
In general, most of the "wordpress" plugin for TinyMCE has to be rewritten, tiny_mce_gzip.php needs changes, autosave.js needs changes and the css around the editor needs adjusting - mostly in Safari and Opera.