The iTunes link to High School Musical was accessible and offered a 1 hour 39 minute Disney Channel original TV movie. This 487MB file represents the first full length movie content that has appeared on iTunes. The movie was originally available for only $1.99 which was the same price as most iTunes Video content.More info over here. More movies are expected soon as Apple is believed to be developing a new iPod video with a bigger widescreen display. The expected release date is around April 1st, the 30th birthday of the company.
This content may have been posted prematurely, as the movie became inaccessible shortly after the original news item was posted. It has reappeared, but is now priced at $9.99.
Apple iTunes to sell movies for $9.99?

Mac Rumors reports Apple is now selling a full-length movie on iTunes for $9.99. It was offered for $1.99 yesterday but that was an error it seems: