As a Nintendo fan I'll buy these systems for even a few of the first party games alone.
there's a new Zelda(wii) coming out November. there's a new Mario(3ds) coming out November. Kirby will be seeing a new game soon. Pokemon is due for an announcement within the next year or so... Look for it, kids are still crazy for Pokemon. I think in japan monster hunter is big, that's coming out soon. Dragon quest games also tends to sell lots of units.
As for marketing, People actually thought the Wii-u controller was either the entire system or just another add on to the Wii when it was presented at E3. So ya, Nintendo should improve its marketing.