In an interview with Aonuma about Hyrule Warrior’s, Aonuma himself has hinted that Legend of Zelda Wii U maybe more than just a single player game:
The two-player functionality of Hyrule Warriors is actually something that has traditionally been done in the Dynasty Warriors series, but they’ve changed because of the hardware and the second screen on your GamePad. Instead of having a splitscreen on the television, you have one-player playing on the television and one on the GamePad. When I was talking back about making Zelda more than just a single-player experience? That’s something you will see in the future, maybe next year.
Source – http://www.nintendolife.com/news/2014/06/eiji_aonuma_hints_at_the_legend_of_zelda_on_wii_u_being_more_than_just_a_single_player_experience