Pro: Get's people excited.
Allows people to contact Nintendo for suggestions.
Nintendo first to announce 3D handheld.
Some other stuff I don't really care about posting.
Cons:
Early announcement of new DS will lower sales of the DS's currently on the market.
Looks like you got most of it taken care of...
Been away for a bit, but sneaking back in.
Gaming on: PS4, PC, 3DS. Got a Switch! Mainly to play Smash