Hopefully the scene will keep going, though, like it did with the Wii, to try to keep finding new holes until the end of the system's update life.
This gen of consoles is kind of a dead end. There's a reason the 360/One and PS4 homebrew didn't really get off of the ground.
With everything centered around NNID's and the Nintendo Network, vulnerabilities aren't going to stick around. Let's look at how each exploit would play out on the Wii U/3DS:
Bannerbomb
New exploit allows homebrew!!!!!!!! Amazing!!!!!
*Fun for like 2 days-7 days*
.......
New update adds a cool feature! Update today!
*People turn on their devices and the update is already installed/being installed and the bug is patched in it*
*Some users have the update servers blocked on their routers, but can't download new games, play new games, play online at all, post to miiverse, etc.*
*Console is basically useless for these users until they update*
Smash Stack
New exploit through game allows homebrew!!!!!!!! Amazing!!!!
*Fun for a day*
.......
New patch for Smash Bros! Update today!
*People can't launch the game until the patch is installed, can't play online, etc.*
The only real workaround would be to have a way to pull in some of the new features to old firmware selectively, spoof your update version number, and/or create a custom firmware backend and update users as new updates come out.
Right now we don't understand or have access to the lower level code to do any of those things, we simply are crashing something and opening up an app. Unless we get kernel access somehow (which I suspect we have on 3DS, not Wii U) we won't be able to even install a channel - and if we do install one, if a new update comes out we're in trouble again because we have to figure out how to change the system menu info which no channels normally have the permissions to do (which requires another exploit which we likely don't have, leaving us sitting ducks for an update to roll out and wipe our progress)