DEFINITELY a Rick Text Editor.
And email notification would be nice (you posted a reply to me on another thread that this was something you were considering when you got around to it . . . you also said that RSS feeds were already an option, but for those of us that have a primitive dial up, maybe the email notification option would be better).
A "preview" post feature would also be good. Right now you can sort of do that by submitting and then editing, but that is a workaround and it only "lasts" for as long as you can edit (which I think is 15 minutes after you post). Sometimes it takes a little longer if you want to modify the post substantially, and the 15 minute edit function sometimes "expires" (this happened to me once). A "preview" might prevent that from happening.
I said it before in another thread, but I'll say it again: My compliments on your maintenance of this forum, especially if it is, as it is, on your own time and dime.