When does everyone think we're going to get the next Nintendo console? They originally stated that it was scheduled for a much shorter life span (2-3 years) than most major consoles, but that was obviously before they realized that it printed money.
I personally can actually see them releasing a new one sooner rather than later. Next year they might hit us with a new DS, then the next year with a Wii 2.0 or something to that effect. It would be a good move, too, in my humble opinion. Suddenly, they'd have virtually perfected motion controls via implemented WiiMotion+, and the price for HD graphical components would've come down considerably so they'd still be able to make a nice profit. So they drop the price on the original Wii to $150, then launch a Wii 2.0 at $250 with full backwards compatibility and 360/PS3-level graphics. It might take some heat initially, but it'd be a wonderful move financially. With backwards compatibility, both systems would be able to sell concurrently with nobody being left out in the rain, and at a sub-$300 price point the 2.0 system would still be a relative bargain.
[What follows will be some more of my ideas, but they're more rambling that anything. Feel free to skip ahead. :D]
-The 2.0 Wiimotes would be the standard Wiimotes with integrated WiiMotion+, and the originals would be completely compatible so long as you had the attachment.
-It would maintain all of the features of the original Wii, including compatibility with all games and peripherals. Hopefully, you'd be able to transfer VC game ownership via some sort of cable or wireless system.
-DVD Playback. With the homebrew that's come out recently, Nintendo can no longer arbitrarily leave out DVD playback as a standard feature.