Last year, Titanfall won half the Game of the Show awards from E3 because of its mobility options -- innovative new ideas like pressing the jump button to climb on top of objects, and giving the player characters jet packs in a sci-fi shooter.
This year, Nintendo reveals a shooter that's all about mobility: you can leap directly into the action as soon as you spawn, raining inky death from above as you fall. You can fly across gaps, slide up walls and beneath gates. And it isn't so simple as pressing a button: you can only perform these feats on paths you've made for yourself with your gun. This requires actual foresight and strategy. Swimming through ink also replenishes your ammunition, and you can use the ink for stealth. The game's core mechanics are inseparably bound together: you can't move if you don't shoot, and you can't shoot if you don't move. These mechanics enforce planning ahead and being fully aware of your surroundings at all times.
I can't believe I have to explain this. Not only does this game have excellent design (yes, we can determine this from what we know right now!), it is completely unique and doesn't play 95% identically to the modern "standard" like almost every other shooter shown in the past several years. That's why people are talking about it! Not because it's made by Nintendo or because it's part of a dry release schedule. I'd go so far as to say that if this game looked shittier visually and was a bit more boring to play and was third-party, everyone would be inking themselves over it.
Oh yeah, I should mention that single player and multiple game modes are already confirmed, so it's easy to conclude that Splatoon will be meatier on content than Titanfall was.
But OP thinks The Division looks good so I'm probably wasting my time in this thread.