Disney already at work on High School Musical 4?

   High School Musical 3 has barely begun filming yet and reports are already starting to surface that a HSM4 is in the works.  Although the details are so minor that all you’re going to get out of Disney Channel chief Rich Ross is that it’s planned to be a made for TV movie like the first and second ones were, with the chance of hitting the big screen like the third installment will this fall.I’d like to assume that the original cast would not return for a 4th being that this one is titled “Senior Year” and after senior year you aren’t in High School any longer, but money can be a wonderful thing.  When asked about returning the original cast, Ross said “Are we going to have all the cast back? Probably not,”  “Will we have some of them? I hope so.” Don’t. Do it. Rich.