The HSM Tour has now finished in the States so filming on the sequal will commence soon. Found this today:
Disney plans "Haunted High School Musical" feature
Walt Disney Co. said it will follow up on the success of its "High School Musical" made-for-TV movie and franchise, by releasing a big screen movie, "Haunted High School Musical" in 2008.
The original "High School Musical," made for $4.2 million, was a Romeo and Juliet-style musical widely derided by critics, but embraced by fans around the world.
It premiered in 2006 and has been viewed by 100 million people, spawned the top-selling album in the United States in 2006, sold 6.5 million DVRAB worldwide and a concert tour.
Disney on Thursday said "High School Musical" would contribute $100 million to profits in 2006 and 2007.
It did not reveal the plot of the "Haunted" movie.
Disney on Wednesday said first quarter operating income at its cable networks increased $81 million to $453 million, driven by increases at the international Disney channels and domestic Disney/ABC cable networks.
The increase at the domestic cable networks was driven in part by DVD sales of "High School Musical" and higher affiliate and advertising revenues, the company said.
Disney has said it also plans to release "High School Musical 2" this summer on its cable network, Disney Channel.
"(High School Musical) skyrocketed to heights never before achieved by a TV movie, so it's only fitting that its next incarnation should be as a major motion picture," said Gary Marsh, president, entertainment, Disney Channel Worldwide.
Internationally, "High School Musical" has aired on 26 Disney Channels worldwide and broadcast networks, reaching over 100 countries.
Source:
Yahoo
BUT I shall be watching when it's on the BBC just 'cause I can. 
In one of the takes, Corbin (Chad) played a prank on them and when he was suppose to cut in at the end when they nearly kissed he didnt cut in and they were told by the producer to just keep going because thats when he gets his best shots if they just keep going with the flow. So because he didnt cut in they kissed and everyone was shocked that they had done it because it wasnt in the script. If anyone wants the video of Vanessa discribing what i just did (so you can hear it from her own mouth then just ask and il post it)