This bug is a little obscure, but I thought I'd bring it up here so a) a moderator may be able to pass it along to someone relevent, and b) you guys can test it on your systems to see if it's reproduceable.
My gamepad recently underwent a little damage, so we packaged it up and took it to the post office today to be sent in for repairs. On the way home I picked up a pro controller (been meaning to grab one) so I would be able to play Hyrule Warriors while our gamepad was absent. I got home, fired up the system with one of our Wiimotes that was already synced to the system, hit Home, then clicked on controller settings. Here's where things got a little buggy.
When moving the pointer around the screen while inside the controller settings menu, there would be a bit of stutter every few seconds. Normally, when you hover over a button in this menu (and all other menus), the system sends a slight rumber to whichever controller you're using. If the stutter occurs in the same frame that the cursor enters the borders of the button (thereby triggering the rumble), the controller will receive a major rumble when the stutter ends/the signal cuts back in.
My guess is that this stutter arises from the fact that the system is searching for my gamepad, but there is none currently connected to the system. If one of you guys wants to test this by navigating the cursor around in this menu with and without a gamepad connected, that would be great, otherwise I'll wait until my gamepad is returned to test this.
Again, this is a very minor bug, and it's fairly rare that a user is using their Wii U without their gamepad, but I figure I'd bring it up anyway. I should note that this occurs with every Wiimote we own as well as the Pro controller, so it is indeed a software bug and not hardware (at least on the controller end). I should also note that the signal experiences no stutter in any other menu or in-game, so Wi-Fi signal distortion seems to be out of the question.
Cheers!