We've got it on pretty high authority (literally, the highest authority - Variety and The Daily Mail) that it looks like Christoph Waltz is on board for the next Bond flick, aka. Bond 24. Little more than that for now, but check back later as we'll keep this up to date.
For reference, the tweets that started it all:
Christoph Waltz Rumored to Play Bond Villain http://t.co/Dd8J2S58Gs