This could so easily have been a Mario game, too, with the Mario Sunshine similarities and the squids resembling Bloopers. Maybe they realized that Mario is a little overexposed.
I didn't see the sales potential in the game. Way to prove me wrong, Nintendo.
Not to toot my horn, but I
basically called that
in my pre-E3 prediction last year (scroll through comments), under the title
Mario Paint(ball). Everything that Splatoon is, is pretty dead-on accurate to what I predicted, minus the Mario theme (and that damnable lack of Voice Chat!), complete with the avoidance of red paint.
I'll just assume my other predictions -- Kid Icarus 3D Platformer (by Retro?!), Startropics and Pokemon MMO -- are being held for a massive NX reveal.