Bad news for you tv lovers, not all Nintendo Switch games are going to take advantage of the console’s dual TV/portable ability. Any game that requires touch screen operation won't be able to be docked to the tv and still playable.
Hopefully Nintendo makes the Wii U gamepad useable at some point to fix this issue.
I think this is good. Why have a hybrid system with limitations? The more options we have the better!
If this thing is meant to replace their handhelds, I expect to see more games with touch controls. Also, the gamepad was never really good at being a second screen. Two screens worked fine on the 3DS because they aren't far apart, but on the Wii U, the distance is too great, so you either spend all your time scaring at the gamepad, or ignoring it in favor of the TV.
Eh, like @benoit489 said, if they use it as a kind of separation between handheld focus games and sort of replace the 3DS I think they will probably be okay. I just worry with Nintendo's often slow output that one of these functions (either handheld or TV docked) will be left with a short lineup.
Getting their handheld and console sectors into a rhythm would be best for the Switch. If you look at 2013 for the Wii U and 3DS, there were enough games to fill a year:
Lego City Undercover
Game & Wario
Pikmin 3
New Super Luigi U
The Wonderful 101
Wind Waker HD
Super Mario 3D World
NES Remix
Animal Crossing Plaza
Pokemon Rumble U
Fire Emblem: Awakening
Luigi's Mansion: Dark Moon
DKC Returns 3D
Brain Age
Animal Crossing: New Leaf
Mario & Luigi: Dream Team
Pokemon X & Y
Link Between Worlds
Mario Party: Island Tour
I imagine they could do even more once those teams unify and start sharing secrets and assets.