Recently, I did a quick hack of ProjectPier to allow the use of textile editor but there was one challenge. E-mails being sent weren't formatted. So I decided to make a few changes and now ProjectPier has a fully functional WYSIWYG editor (nicEdit) and sends e-mails in a valid HTML format.
Download: ProjectPier WYSIWYG Editor
* Credit: nicEdit by Brian Kirchoff | "Adding TinyMCE..." posted by Matt Gibson