This is one of those times where I'm reminded that having the ability to use four GamePads at once could [imo should] have been truly brilliant and potentially generation winning. Realizing the idea of the GamePad to it's full potential as I see it by allowing up to four to be used at any one time for local play is how Nintendo really could [imo should] have blown people out the water.

Note: It's 4 rather than 2 or 20 or whatever because historically (since the N64 and even before it in a few cases) 4 player local multi-player has actually been a 'thing' that many games and consoles have widely/fully supported and so it would have made sense to support up to 4 GamePads in this case too imo. It's just the right number in so many ways. At the very least however, the ability to use 2 GamePads should have been there from day one with a few games that actually support this feature available right out the gate too imo.

Imagine a 4 player local multiplayer game of Madden with each person making their own private play calls on the GamePad while the main game is shown on the TV screen... Imagine a 4 player game of Splatoon with each person able to play on their own private screen and the map/score/etc screen is displayed on the TV... Imagine a 4 player game of something like GoldenEye with each player playing on their own private GamePad screen (no screen watching here)... Imagine a 4 player game of Poker with each player being able to see their own cards privately on the GamePad screen and the main cards and table shown on the TV screen... Imagine a 4 player game of Scrabble with each player seeing their letters privately on the GamePad and the main board shown on the TV... That's just a few simple and obvious implementations that immediately popped into my mind but the potential for something like that could [imo should] have been truly mind boggling.

Alas...Not happening because like so many of Nintendo's potentially brilliant ideas in the last few generations it had the idea but didn't really see it all the way through to it's full and natural conclusion and realize it's full potential imo.

Still, I think the Splatoon devs are going to do a great job with whatever they decide to do for this game given the limitations.

Note: Don't concern yourself with trying to imagine the logistics of how it might have been possible or not to get 4 GamePads working on the Wii U or even how it could have been made practical and affordable etc because unless you take more than a few minutes to think about it in great depth (coming at it from fresh angles and ways of thinking etc) you'll just come up with ill-conceived stale reasons for why it simply couldn't happen, based solely on your current understanding of the situation and circumstances and little more, but rather just imagine what could [imo should] have been if it had actually happened...