Have the specs of the system even been released?
They're two different markets, basically, I don't think anyone will be comparing the two. Nintendo certainly isn't going to ditch the Wii gold mine in favour of 3DS projects; if anything changes, it will move to Nintendo's next home system, if it's coming soon. And it might just be.
As for third-parties, they aren't going to favour the 3DS over Wii any more than they favour the current DS over Wii.