Surprise appearances at the Oscars??

So, do you think there will be some huge surprise appearances among the presenters which haven't been officially announced??

Like, i don't know..

Jack Nicholson for Best Picture?

(I want to remind that technically it's the 50th Anniversary of One Flew Over The Cuckoo's Nest's Best Picture win).

Martin Scorsese for Best Director?

Or

Christopher Nolan for Best Director?

Thoughts?