Just as a thought, the Wii may live for far longer than most people expect ...
I'm a firm believer that Nintendo will work on shrinking the Gekko/Broadway and the Flipper/Hollywood processors so that they can fit them on one chip in order to reduce the manufacturing cost of the Wii and to include them in a future handheld system; the handheld system may not be running at the same clock speed as the Wii, but it shouldn't need to be at that much lower than the Wii with how low the power requirements of the Wii already are. This system will (most likely) be released in 2010 as the replacement for the Nintendo DS.
With how popular the Wii is, if this handheld system is even close to the popularity of the DS or GBA, the architecture of the Wii will continue to be the most popular gaming hardware from 2010 until 2016 (at the earliest); at the same time it should be (fairly) easy to maintain backwards compatibility with Wii hardware regardless of whether you continue forward with the same architecture due to how low performance the system is compared to the hardware that will be available for its successor.
Even with the massive growth in the industry, most game developers simply can not afford to put the resources towards game development that the HD consoles currently require (and next generation consoles will require) and be successful companies. Many of these developers will hold out as long as they can before jumping to the next generation.
The last consideration is consumers. The market for a videogame system that is $75 (or less) in both the developed and developing world is far larger than most people probably suspect. By the time 2011 rolls around, Nintendo will easily be able to manufacture the Wii at a low enough cost to sell it for a tiny price and will have a massive library of games which have already broken even (and turned a healthy profit) which can be sold for $20 (or less).
Basically, with how widespread the hardware for the Wii will be, how low the development costs are, and its ability to sell at a lower price than any previous console it is possible that the Wii will still see regular software releases 10 years (or more) after it is released.
