I'm going to give you your Wii U E3 2015 Nintendo.

[flagstaad]

I want them to improve their relationship with third parties:

-A new JRPG for Wii U from Square-Enix maybe using one of the new IPs that are having success on the 3DS like Bravely Default or Final Fantasy Explorers, Kingdom Hearths 3 port for the Wii U
-PES 2016 for the Wii U with an exclusive mode or a Nintendo team or something simple that could attract the players
-A good fighting game being ported to the console with an exclusive characters (Namco-bandai soul calibur with link?, Street Fighter IV ultra super something edition with Little Mac? something else?)
-Ultimate Monster Hunter 4 U for the Wii U from Capcom
-A game like Marvel Ultimate Alliance or X-men Legends, exclusive or not I don't care

And then all the first party stuff that you already mentioned, specially rooting for a Paper Mario game on the lines of TTYD.