Fix your Swing-Bugs first...
I've yust took a look at the Editor-Demo. Ok, nice to have a bit more around now. But its useless in productive Applications as long as main Bugs in the JEditorPane and it's HTMLEditorKit aren't fixed.
I think you had a good reason why you didn't add a "Bullet-style List" Button. Lists (and many other Elements) are not correctly handled by HTMLEditorKit, especially by the remove function.
Also in your example position the cursor between nonbold and bold text (on one line). You will notice a state, where the bold-button is down in the toolbar, but when you type text, the text appears nonbold....
I could add some more examples here. Should I?
So please: concentrate on fixing bugs. I think that's why so many people ask for opensourcing Java. Bugs would be fixed sooner (sometimes it takes less fixing a bug than providing a testcase...).