From the Force.net
beware of spoilers below!
There's a new Character In Episode Three.
During breaks on Stage 7, Ewan, Hayden and a mystery actor would sit in buggys outside the entry door on the backlot and stretch their legs. The last time they did this was just two, maybe three weeks ago. The mystery actor was there several days in a row and looked a little like an albino Jedi with white eyebrows and a creamy white beard similar to Liam Neeson's beard in TPM - he had quite pale skin and appeared human, and about the same height as Ewan McGreggor.
His gaze was disturbing to behold (perhaps it was the young face behing the short white beard and hair) and he was dressed as a Jedi and carried a lightsaber. Sometimes, Nick Gilliard (choreographer) would sit in the gutter with them. This "Milky Bar" kid was mysterious in that he was often there in uniform with the other two Jedi.
Hayden's costume was dark brown, almost black pleather and all three wore great big boots. The dark leggings on their costumes each appeared dirty as though they'd been rolling in talc. They would always look up to see who was driving past them and seemed bored whist waiting for the sets to be prepared for each take.
When the alarm sounded, they would enter the small door on the side of the stage and the amber flashing "Filming In Progress" light would come on again. But this new character looked very much like an albino Jedi. His costume -from memory- was darker than Ewans, much like Hayden's.
I dont know if anyone else thought this, but the first name that came to mind was Jorus C'baoth (SP) from the Thrawn Trilogy. The description is a dead ringer. Look at any pictures of him and you will know what I mean. I know a EU character will appear but could this be the character? Just a guess.

