I'd avoid sweeping statements like that - it's not entirely accurate (though is along the right lines). There's more to it than that. Nintendo has certainly targeted the Wii to the casual family audience, but they've proven themselves worthy competitors during the N64 and Gamecube generations. Despite the name, the Wii U looks to be a return to those more traditional days, and Nintendo have refocussed to appeal to the hardcore audience more. There's still an aim to casual families, but whilst taking more notice of hardcore needs, with improved online capabilities, accomodating 3rd party games - basically catching up with the standards we expect from systems now, and the things that make the 360/PS3 'hardcore' consoles. We'll see how the Wii U goes, but it looks promising.
Also, the Wii did have Mario Galaxy, possibly the best game of this generation. Top five at least - and this is from a guy who is usually critical of most of Nintendo's recent offerings.
I'd say a late 2013/early 2014 launch for consoles is realistic. They really won't want Nintendo to have too much of a head start.
