(nearly) Halfway through the life of the Wii?

Nintendo's previous console chronology:

NES: 1985 - 1992 (7 years)

SNES: 1992 - 1996 (4 years)

N64: 1996 - 2001 (5 years)

Gamecube: 2001 - 2006 (5 years)

Wii: 2006 - 2011? (5 years?)

Based on Nintendo's previous console lifetime, as you can see above, could we be seeing a new console in a mere 3 years? I for one think so...

A Truly Update Able Console
Now, given that the Wii is Nintendo's first update able console, of course this expands it's lifetime dramatically. The control interface of the Wii is like no other, peripherals such as the Wii Balance Board and soon to come Motion Plus and Wii Speak also push the life of the Wii forward.

The Human Factor
The Wii appears to be more than just another console, the current and seventh generation of gaming has brought us into the game. The Wii's Mii characters have brought a feeling of self into gaming, putting the baseball bat, tennis racquet, and the like in our very own virtual hands. Playing online with friends has never been easier, bringing that multiplayer factor into the room, yet not in the same room.

Menus, Operating Systems, Wifi
Console Design has changed over the years, when consoles started out it went like this:
8-bit
16-bit
32-bit
64-bit

Now, we see consoles with entire operating systems and large amounts of processing and graphics cards, system menus and DVD's.

The "Casual" Gamer
Nintendo has targeted everybody with the Wii, many Wii owners have never played video games before. There is an undeniable force that draws non-gamers to this console for many reasons. People seem to "just want it" then as more people get it, more want it because others have it. A vicious money making cycle, so why would Nintendo want to stop this any time soon?

Piracy
Can piracy kill a console? Yes, in extreme cases it can. Reports show that the rate of sales for the Sony PSP to PSP games is 0.7. That's 0.7 of a game being sold to every 1 PSP. What's the bet that the PSP won't be on sale for much longer?
Of course with the Wii having a large casual gamer fan-base, most people are oblivious to piracy, let alone how to do it, and most of those that are aware, won't go to the trouble. I'm estimating that a max of 2% of Wii owners endorse piracy.
To avoid piracy, don't go with a common media like DVD's. If Nintendo brings out a new console, it would be in their best interest to go with something like HD-DVD, a dead media, killed by blu-ray, or something completely new.

Summing Up... Tell Me What You Think
I think Nintendo could be thinking about releasing another console in 2011 or 2012.
Where can they go from here?
Should they just keep updating the Wii?
How do you build on motion control?
What will be the target audience?
Do they move away from common media or just go with Blu-ray?