My custom editor-style.css file was not loading in WP's TinyMCE editor. After some testing I discovered that WLCMS 1.4.X was the culprit. Disabling WLCMS allows editor-style.css to load.
Another site using WLCMS 1.3 and WP 3.2.1 loads editor-style.css just fine. So I'm guessing this issue has to do with the major changes to 1.4.X.
Please fix ASAP so I can start loving WLCMS again!