It is now common knowledge that Episode VI was originally rumored to be titled Revenge of the Jedi, and that even some early licensed merchandising and posters had this title on them. I've heard two explanations for the change to Return of the Jedi:

1. Simply the filmmakers decided that a word like Revenge was unbecoming of a Jedi and decided to change it

2. That "Revenge" was intentionally leaked as the title so that pirated merchandise could be spotted.

Is there any truth to #2?

I think it's mostly due to the first one. Revenge totally goes against the jedi code hence .

Plus I've seen/read interviews with Lucas saying they changed it for that reasaon

Also if number 2 was the case, they probably would have tried it with episode one given the huge amount of merchandising behind that film.

When they were filming ROTJ, they used another name altogether as a cover, but I can't remember what it was. I'll have to look in the book with the LD set tonight.

Blue Harvest

Blue Harvest was the code name for the movie. They told the locals it was a horror movie.

Plus, wasn't The Wrath of Khan originally supposed to be The Revenge of Khan, and they didn't want to have the title be that close to the Star Wars film, so they changed it too?

I remember the "Revenge of the Jedi" marketing (or maybe just reading about the upcoming movie back then), and was suprised when the change was made. As I remember it, it was due to the studio deciding that the negative connotation of "revenge" was not in line with the Jedi, and "return" was more appropriate.

back in the dark ages, way before the internet, some of the best inside info on in-production genre movies was found in Cinefantastique.
they first leaked the info that the "other" cryptic comment in ESB was to refer to Vader/Anakin who would turn in the last act and destroy the emperor.
though they didn't have that quite right (most people take the 'other' to mean leia) and they didn't seem to know that leia was lukes bro, they did give a paragraph discussing the apparent witlessness of the oxymoronic title. it was several months after that that Lucas officially had the old posters pulled and re-titled it.
this was in fall of 82 if i remember right.

btw, posters weren't the only thing with the old revenge title.
a trailer (which in retrospect was by far cooler than the actual finished film was) was released.
i bought it off a projectionist at the local theater for about $8 about 7 months before the movie came out.

Again, Do you think this was an after-the-fact decision that Lucas prefered one title over another, or was it a fancy ploy to deter bootleg merchandise?

Is "Jedi" in ROTJ singular or plural?

Singular: the return of Anakin
Plural: the return of the Jedi Order (beginning with Luke)

If it was this day and I age I would think that is a good reason. Since bootlegging is much easier now then it was back then.

can't we just put all the questions in one thread? Or when should I expect to see: "Yet another ROTJ question"

In the current context, I think it means the order.