Maybe I can't read, or I didn't read this thread carefully enough, but no one has explained what this Dialogue Editor is. What is it, what can you do with it?
But like WindStrike said, item Editor allows for so much amazing stuff. Enemy editor is nice, but since you can already make custom enemies and bosses quite easily that's not number one priority. And the Dialogue editor... if I just knew what it was I could make a comment about it... :p