The whole reason why the Wii is a Nintendo Gamecube *2 is because Nintendo were being conservative with the hardware. They were taking a risk on the interface so they needed a system which was easy and straightforward to develop/prototype new game ideas for and wouldn't break the bank in terms of development/hardware costs that could be sold for $200. The next generation Nintendo console isn't taking a risk on the interface anymore so theres no reason to be as conservative on the hardware and now they have many new game ideas they don't have to worry as much about a more expensive system to develop on as they have far less need to prototype risky game ideas.
I don't see any reason why they would delay a next generation console if the need arose. However noone can really say what their priorities truely are in the console space except perhaps that they would want their next generation Wii to encompass a larger proportion of the overall market and if they need more performance to do so then so-be-it. Given modern architectures they could easily make a system which is powerful by todays standards within the heat/packaging restrictions of a console around the same size as the current Wii.
The performance benchmarks aren't being set at what a dedicated desktop PC is capable of anymore. The real benchmark is the semi-capable laptop architecture as laptops are far outstripping the desktop machines in terms of user adoption and their performance just needs to be relevant compared to $600 Laptop computers with dedicated graphics. The next generation Wii will probably be powered by AMD second and third bin laptop Fusion chips which for whatever reason cannot meet the TDP or clock requirement for installation in Laptops.
Whats clear to me is that one thing Nintendo has to do is stop bucking the entire ecosystems paradigms entirely. This means that multiplatform games need to be portable to their system both from the current DX9 dynamic duo and the future DX12 Speed demons in order to have a well balanced library and thus a well balanced ecosystem. Having a more powerful console released sooner is not about the expanded market opportunities, its more about ensuring that the core markets Sony/Microsoft hold aren't closed off to them entirely as both Sony/Microsoft entrench their positions with their respective userbases whilst leaving Nintendo little hold over their own expanded market.
Tease.
