I bet Nintendo will come out with a Wii very soon. Like mobile said, probably close to E3 2011.
If they don't, Nintendo will be far behind everybody else. Microsoft and Sony have motion controls. That added with HD and 3D, the Wii is in a losing battle.
I'm not completely convinced a new Wii will come out this year though. I bet it gets announced and then comes out sometime in 2012. But the world is going to explode in 2012, so it really doesn't matter. lol =P