I was going to start a thread asking who would Ernst Stavro Blofeld be played by if Christoph Waltz is telling the truth and it's not him and also if it's not Andrew Scott as others are positing. But then I saw this old thread and figured I should post my thoughts here.
Anyway, I came up with two candidates that EON could conceivably be keeping up their sleeves to surprise us with their casting as Blofeld. The likelier actor is Gary Oldman. He plays a great and threatening bad guy and is young enough for a return installment(s) as Bond's arch-enemy.
The other candidate would be my personal top choice simply because I love his voice and his slow, smooth delivery which can be very commanding and menacing and totally in line with Eric Pohlmann's iconic Blofeld--and that candidate is Hugo Weaving.