This is one of those threads where everyone is right. Yes the wii u surely could have slightly altered versions of games that cater better to its audience and the hardware but no, in certain circumstances you would want the full game experience and not something cut back or simplified for wii u.
I think double-dipping isn't really considered as an industry that much. Yes they have exclusive features that favour one platform or the other but you don't see games released on multiple formats that you actually will buy for multiple consoles because the experience is different. I think if they realised that many ps3 owners also own 360's for example they might make the game a slightly different experience so the owner buys both if he really likes the game and fancies playing a slightly different experience of the same game on another console.
Generally though I think for weak hardware publishers cut back the experience and yet often charge the full price. In the past some games were developed on ps2, psp and wii. They were the lesser formats and got a cut down gaming experience compared to 360, PS3 and PC.
