I have a feeling that, despite what I see as a misstep with the tiered pricing (should've just been one $299.99 model in my opinion), the Wii U is going to be extremely successful. I say that because gamers haven't seen a new home game console since 2006, and it'll probably be 2014 before they can get their hands on the next offerings from Sony and Microsoft. I think gamers are ready for something new right now, and Nintendo is here to deliver.
I've seen the term "Wiimcast" recently, but I don't think we're looking at a Dreamcast situation here. The Dreamcast was released just three years after the N64 and one year before the PS2. The Wii U is the first new home console in six years instead of three, and I think the probability is pretty high that it has a lead time of two years on the NeXtbox and PS4.
Even though I'm a little upset at Nintendo for the uncharacteristic tiered pricing, I already want a Wii U. Not badly enough to pick one up at launch, but I could definitely see myself getting one sometime during the first year of its lifespan. It looks like a good, solid, fun system.