Has anyone seen the new ROTK tie-in books? The juvie photo guide has a few clues about the cut Saruman scene. It mentions that Gandalf went to Isengard. It seems that Pippin finds the palantir while in Edoras. I have a feeling that the cut scene may be narrated by Gandalf in passing. From a story-telling point of view it makes sense.
However, another little spoiler for you, one of the questions in the LOTR Trivial Pursuit is "who kills Wormtongue". The answers is Legolas. Not the same as the books for certain. So, who goes to Isengard? And what sort of story impact will this cut scene have?
That's the problem with merchandising, I suppose.