This is Nintendo's standard upgrade strategy. They always provide BC, such that, eventually, they can eliminate it (like the GBA slot was eliminated the DSi), but provide "partial upgrades" at every stage of the process.
The DSi will eventually replace the DS entirely, and DS games will give way to DSi/DS combo and then DSi-exclusive games only, if history teaches us anything.
I would be downright shocked if the Wii didn't follow a similar upgrade path, considering its evolution from the GameCube. Wii HD, using regular Wii discs with upscaling for standard Wii titles, and "use 720p and more texture memory" options for new "combo" titles? -- right up Nintendo Alley.







