@Pezus: You are right but you are thinking about it the wrong way (the 750K number is correct)...your math is saying it sold 15% of what it sold the rest of the year. What you need to do is find how much 3DS sold through November in 2012 and multiply it by 1.15 (15% increase). Then find how much it sold through October in 2013 and look at the difference.
@Figgycal: that confirmation that 2DS is included looks to be on the side of VentureBeat, not NPD so it may just be speculation...not 100% sure though