even when Nintendo releases that Wii with DVD playback, it will still be the same Wii in terms of gaming capability, graphics, sound etc.
Nintendo is training developers (and even themselves) to focus on gameplay, control, interaction with the Wii Remote and Nunchuck, without any large upgrade in CPU and graphics. once developers become used to making new types of games &gameplay, Nintendo will probably settle for a next-gen console that is somewhat more powerful than Xbox 360 and PS3 in terms of graphics, even if not on par with Xbox720 and PS4.