You didn't think about this post as all did you?
The GameCube had an add on that allowed people to play game boy advance games on the tv. Think of this as a program that performs a similar function. The game I still a 3DS game and runs on the 3DS, this just streams to the Wii u and has a texture pack that allows for HD (or at least higher quality visuals). Still a 3DS game, just with a way to continuously sun with the Wii u so you can play on your console while you are home and your 3DS is in range
The 3DS will always be worth owning because it is a portable and I can always keep it with me. I've always gamed a lot more on the portable side than console side.
Well, I thought you meant playing 3DS games like some sort of Virtual console thing. Streaming 3DS games to your TV via Wii U, that makes more sense.