It's going on till Sept 30, 2006.
It's 1:30 to 4:30 daily at Epcot in Innovations West...just ask a CM.
It's one free photo per CC...but you can probably go another day and get another one...I've heard of DISers doing this.
They give you a photopass card for this and you can go and pick it up right away.
Yes, you must show them your CC.
The characters are subject to change and rotate.
It's definitely getting more popular and thus the line is getting longer. I waited a half an hour last Oct 1.