I would be extremely disappointed. He brought such magic and life to the films, and portrayed Gandalf just as I imagined him to be.
Could I blame him? Well, I don't think he'll leave...
"It never happened..except somewhere in our hearts. And yet, there was Hobbiton in three dimensions and smoke coming out of the holes where they live underground. And I believed."
From such strong words, I would highly doubt Sir Ian would leave such a place which he seems to love so much, and I can understand why.
EDIT: 200th Post! Woo-hoo!
And such a great quote in it. It seems fitting to be the 200th.