I... I don't understand. This question confuses me more than it should. To me, Wii U's tablet IS Nintendo's "response" to consumer tablets, so I can't imagine on any level why Nintendo would decide to release a tablet with a capacitive touch screen designed to compete directly with iPad or Android.
Given that Nintendo has no true investment in software beyond video games, this would mean that - in order to compete in a real tablet market - Nintendo would either need to manufacture an entire software & app ecosystem OR work together with Android, etc. I don't see either happening.
I see Wii U tablet as a perhaps unintentional response to the "tablets are now more ubiquitous for gaming" hype that everyone's on. It suddenly becomes THE definitive gaming tablet if you think of how you can stream the game instantly into your hands.
Lazy Saturday afternoon. You're watching a game on television, but you also want to occupy your hands with a quick game. You pull out an iPhone, maybe play Scramble with Friends or Angry Birds. Then, seeing the Wii U tablet on the table, you turn it on and play a real game on the tablet. Maybe it's Mario, maybe it's a Wii Ware game. But the point is that it can conceivably compete for people's attention in the house in a way that consoles haven't done before.
