Wii U shelf space at my local stores is already noticeably down even from last year. I bought Smash 4 this week and it was actually not super easy to find (one of my Best Buy's only had one left on the shelf) and let's not even talk about finding the Gamecube controller adapter which is basically impossible save for Ebay. I would guess that stores will probably get one last shipment of a lot of the more popular Wii U products for Christmas but I would suspect that you will be going on Ebay for Wii U-anything starting in early 2017.