Motion control for the Wii and PS3, and Natal.
At first I wasn't too upset about it when it was just the Wii, I thought it would fizzle out by next generation. Now it doesn't seem that way. Natal especially; I don't want to go home after Class and work everyday and then jump up and down in front of my T.V. waving my arms to play a game. This is why I hardly touch my Wii, only occasionally playing Brawl... with a GCN controller, and won't be giving Natal a second look.
I think a lot of people disagree with me, though. It won't bother me a lot as long as they don't take away my good ol' fashioned controller, which Nintendo already has..... OH, GOD, IT'S BEGUN!!!