There's a big question not being asked in this thread, which is competition.
Wii Fit Plus is going into a red ocean. EA and Ubisoft are out to take over the fitness market with their Fitness and Your Shape series. EA Sports Fitness is already said to be the best workout on Wii, and these series will explore tons of different exercise possibilities over the next few years.
Wii Sports Resort is going into, let's say, less of a red ocean. Most of the Wii Sports clones basically treated the customers like crap, and with dwindling sales have started to disappear. But there are still some out there which will take WSR sales, most notably Mario and Sonic Winter Olympics.
New Super Mario Bros. Wii is going into a blue ocean. It would be at least until Xmas 2010 that a better 2D platformer could come out. Nintendo probably also realizes that it is their biggest hardware driving game, and so will probably have an all-out advertising blitz for it.
Without competition, I think all three games could be in the 20-30 million range. But with WSR having some of it's sales taken away by other Motion Sports games, and with WFP having I think a lot of it's sales taken away by other Fitness games, I see the order being NSMBW > WSR > WFP.
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.
