DS and Wii should perform well again next year. Wii should top 80 million late 2010 as DS tops 140 Million late 2010. Now as I say I'm wondering when Nintendo will do a official announcment about these milestones.
Buying in 2015: Captain toad: treasure tracker,
mario maker
new 3ds
yoshi woolly world
zelda U
majora's mask 3d