Nintendo fans would argue that a Wii U, unlike the PS3 and 360, has Nintendo exclusive titles. But the problems are:
(1) The first party Nintendo exclusives shown were pretty lame. I get that Pikmin has a fanbase, but really its not that great a looking game. At least, it's not a great game to show off a next gen console. You're just looking down at the ground, nothing big and cool and epic. Just the ground. I get too that you can find beauty in small things, a game doesn't NEED to be big and epic to look good. But as a release title, it's not a good showcase title.
Game & Wario looks fun, but it's about as graphically advanced as an XBLA title.
NSMBU looked like NSMBWii in HD. Not impressive in the slightest.
All three of these titles are sure to be fun games, but they fail in the graphics department which is what Wii U needs to push to make consumers aware that it is a step up from their current consoles. As it is, it's not.
(2) The ports, as George mentioned, are so GD OLD. Who wants them? Arkham City will be over a year old! Reggie claimed its a "new experience" with the GamePad, but fuck that. If I spent $60 on the game and beat it on the 360, there is zero reason to rebuy the game a year later. It's stupid. They needed to show an original third party "hardcore" title. And they did...
(3) ZombiU. Hmm. Looks interesting, but really. Zombie overkill anybody? It's a pretty saturated market, zombie games.
(4) The multimedia and entertainment aspects are nowhere near what 360 and PS3 have, and knowing Nintendo they will not be the focus. "But it's a gaming machine first and foremost!", I know it is. But it needs to push these other aspects if it wants to compete.
(5) GamePad battery life is shit. One of the selling points, playing the Wii U while somebody else is using the tv, is stupid. If I'm not allowed to use the TV (what am I, a child?) then I do something else. This aspect will not appeal to the hardcore, because if they are hardcore enough, they'll have total control over their television. It's really a selling point for babies.