I follow Digital Foundry on Eurogamer and this is a fantastic article showing the developers challenges of developing for the WII U and why many 3rd parties were not successful on the WII U. Here are a few snippets of the article
So a basic comparison/calculation makes the Wii U look, on paper at least, significantly slower than an Xbox 360 in terms of raw CPU.
Having worked on other hardware consoles, I suppose that we were rather spoilt by having mature toolchains that integrated nicely with our development environment. Wii U on the other hand seemed to be trying at every turn to make it difficult to compile and run any code. Nintendo had provided an integration of their development tools into Visual Studio - the de facto standard for development - but it didn't work, not even close.
After about a week of chasing we heard back from the support team that they had received an answer from Japan, which they emailed to us. The reply was in the form of a few sentences of very broken English that didn't really answer the question that we had asked in the first place. So we went back to them asking for clarification, which took another week or so to come back. After the second delay we asked why it was taking to long for replies to come back from Japan, were they very busy? The local support team said no, it's just that any questions had to be sent off for translation into Japanese, then sent to the developers, who replied and then the replies were translated back to English and sent back to us. With timezone differences and the delay in translating, this usually took a week !
At some point in this conversation we were informed that it was no good referencing Live and PSN as nobody in their development teams used those systems (!) so could we provide more detailed explanations for them
Thanks to hesido on Neogaf for the snippets Here is the link to the article. Many people attacked Bethesda softworks VP Pete Hines over comments on how Nintendo did not welcome 3rd parties with open arms to their platform. I think this article defends some of the comments Hines made but as many people have pointed out this strikes an eerie resemblance to the PS3 back in 2007.
Nintendo's 1st party will always be a great reason to buy a Nintendo product but the hopes of Western 3rd parties developers returning to the Wii U are very slim.