The editable text control does not seem to do true WYSIWYG. Basic styling works fine and is reflected in the editor but any styling that references a css class outside of the editable text control is ignored. So a style like

.maincontent b {
 color:red;
}

Where maincontent is some sort of wrapping div around the editable text control doesn't show up until you preview the page.

The only way I have found around this is to create a separate stylesheet for the editable text control with a style like

b {
 color: red;
}

and set the 'HTML editor css stylesheet' property on the control to it.

Is this the best I can do, am I missing something?