Watch Dog was always going to be the inferior version of the game on WiiU. Beside it's too early to know if it failed us. Ubisoft as broken every bond they used to have with Nintendo fans by delaying Rayman Legends and now delaying the Watch Dog version on WiiU. If anything Ubisoft as failed us big times.
I think for WiiU owner that don't have a gamin PC or aren't planning to buy a PS4 and Xbox One .... Watch dog is still going to be a great game for them. Nothing else will be comparable on the WiiU. I'm worried about the Watch Dog delay, is there a fundamental flaw to the game that explain the delay. Is the delay from a technical reason or the game simply wasn't fun and would of got killed by the critics? Or is it a financial reason again, personally I think that Ubisoft team working on Watch Dogs ran into issues porting the game over to PS4 and Xbox One. The management at Ubisoft made the decision that this game would hit every console at the same time (other then Nintendo's whose no longer a focus) in order to maximize day one profit. Ubisoft game that have yearly iteration don't have any legs beyond the first month of sales. (first months makes up 70-90% of sales).
As a Nintendo fan, we're getting royally screwed by Ubisoft. But, on the plus side if your patient you can get their triple A blockbuster in the bargain bin just a few short months after release.