Its too late at this point, to be frank. Completely ignoring Move and Kinect (because the situation would be the same if they had never been announced), Nintendo has ignored Motion+ for far too long for most developers to care about it, even if Nintendo makes the Wiimote with the accessory built in. If Nintendo had started bundling it when it first came out, sure, but at this point it is a lost cause.
Plus, Nintendo would almost certainly charge $50 for the controller separately (because they probably wouldn't take the Wiimote or the Motion+ dongle off the market), which means most consumers probably wouldn't bother with it either.
Edited at Fri Sep 24, 2010 1:52:49 PM
Michael: Jodie, how's my schedule look for today? Jodie: You've got a conference and dinner party at the Japanese Embassy regarding wildlife protection. Michael: Oh, yeah...sorry, but I'll have to cancel that. I'm heading out to save America!