Nintendo says they are making more this time, and cords are 5ft instead of 3ft.
I would guess for variety sake(action RPG instead of turn based like FFIII/Earthbound/SMRPG) and it has co-op.
Speaking of what the line-up is really missing is a co-op brawler like Final Fight 3. (only one I can think of atm besides Turtles in Time, which you know there's no way it could have been included)