Intelligent Systems could be developing a new Paper Mario for Wii U. The rumor is based on diluted material, but we could link this information with a previous article related with this matter.
Apparently, an employee from Intelligent Systems mentioned this project to some people at a job expo booth in Japan. Evidence:
New game or remaster? Both options could be possible.
Time ago, Walmart listed Paper Mario on Wii U, therefore, the game has already been mentioned in two different sources.