Nintendo should take respoonsibility of porting 3rd party games themselves - it will lesser the burden of porting the game for the developer.
1) Why not let Nintendo add your game to its console?
**Con- Nintendos porting costs will mean that they will have to give the developer a smaller share of the profits. And then if the consumer buys the Wii U version the developer will make less money on the game.
**Pro- If the majority of people are going to buy it on the mainstream consoles then why not let Nintendo make a port of it for their console and get some extra revenue for no extra cost. Wii U owners may not bother purchasing the game otherwise.
To address the con: They could implement later release schedules to encourage people to buy the mainstream versions of the game, so that the developer will get more profits. And then when the marketing has died down and the game no longer sells for top dollar, Nintendo will port your game for free, give you a smaller margin due to the extra port costs, resulting in the developer earning money that they would otherwise not of had.
Alternatively the developer may consider porting it themselves or creating it for the Wii U's architecture - but if they have the option to give the Wii U version a 'spin' at no extra cost it will be great for all involved.

