The recent upgrade to the Text/HTML module added a new inline editing feature. Inline editing allows you to directly edit the module title and content. Just click on the module title or content and start typing. When you are done editing either press 'ESC' to cancel your changes or click somewhere out of the editing area to save them.
Inline editing only allows you to edit and format text content. Formatting is accomplished by using shortcut keys such as Ctrl-B for bold or Ctrl-C to copy.