I think its pretty much guaranteed they will at this point. Nintendo can try to ride out on the Wii for this holiday but by the next holiday the HAVE to have a new console. The Wii was and IS a great console but the 3rd party support for the system is really falling away and from a tech standpoint its really starting to become dated.
At this point people can get 360's and PS3's for not that much more than a Wii and they have better tech and motion controls. And something that really is affecting the Wii I think at this point is the complete non-support of online gameing. Whether Nintendo wants to get in on it or not it is the future of gaming and pepole want to play there Call of Duty's and Halo's and such online with friends and Nintendo is doing just about nothing to support them. Basically Nintendo was revolutionary this gen with motion control and going after the "Blue Ocean" crowd but the same things that made them hugely successful are the same things that make them in desperate need to launch a new console if they want to be 1st again next-gen.
