The problem is not that Nintendo is abandoning the core gamers (though I think the Wii Sword Duel looks awesomely fun!), but that Nintendo chose to barely address the market at all in their presentation - just quick nods to Clone Wars and Call of Duty.
I think many of us were hoping Nintendo would take an approach more similar to Sony's "Look at all the shit we got coming" presentation. Toss out more footage of Mad World, Conduit, Mushroom Men and Disaster and so forth, rather than choosing to essentially highlight just a small handful of games (mostly Nintendo developed).
I do laugh at the response to the snowboarding game - since when are snowboarding games for teh casuals? Just because it has the WiiBoard? I thought expensive, specialty controllers used to be the hallmark of core gamers? You know if the WiiBoard were originally sold by Sony or MS as part of a new SSX game, core gamers would rush to embrace it. The problem is it has the stench of WiiFit.
I think Nintendo's biggest gaffe was revealing the 1:1 controller a day early. So far as I know, no one saw this coming (ironically Nintendo was the only company no one was expecting to show a new motion-based controller). Reveal that during the presentation, and couple it with a lightsaber game demo... it wouldn't have beaten FF13, but it would have created geekasms across the country.
Imagine if they did what Sony did last year for their SW PSP - Show the new attatchment, and to show what it does... lights go down, cue the Imperial March...out walks an actor comes out dressed as Vader. He pulls out the WiiMote, slaps in the attachment, and begins to swing., with his video avatar duplicating each move. Announce that Clone Wars is being delayed to incorporate this technology, and you've got everyone hooked.