I have heard that the 3rd High School Musical movie will be called Haunted High School Musical, is this true?

That's what I heard, I saw it in an article online. Search around, that'll help you. I also read that they started shooting for it.
But you never know, they can change the title.

~Chrisssy
PS: I really don't like HSM anyway, LOL

Yeah it is

Well, I've heard about it. Although the topic doesn't sound very good for a movie.

I only like the second High School Musical - not really the first movie.

It's also supposed to come out in theaters I heard - but we won't find out until they start shooting, or until it comes out.

~Tink

i dont think so its going to be about graduation

Nope Like Soufriere_Hills Say it about graduation and prom

edit Plot As seniors in high school ,Troy (Efron) and Gabriella (Hudgens) struggle with the idea of being separated from one another as college approaches. Along with the rest of the Wildcats, they stage a spring musical to address their experiences, hopes and fears about their future.

Well, the movie is in talks still - once they start filming, let's hope they'll give out clues. Although I've heard many about graduation from High School, that this would be the topic. It may be the end to the High School Musical movie series.

~Disney