I hope Pearce is indeed playing the old Weyland, and we don't get to see him ham it up too much as his younger self, per today's viral video. Plus, Ridley has a good track record with actors encased in disfiguring makeup or masks (Gary Oldman in Hannibal, Edward Norton in Kingdom of Heaven).
I do hope that Weyland is kept in the background as much as possible, though. This viral vid already goes someway toward spoiling the sinister enigma of the Company, always lurking in the background in the original trilogy. Please, Ridley, don't let this be your Phantom Menace.