Yeah, it's hope but I don't think it's blind hope. Nintendo has righted a couple big wrongs this generation. Hopefully, they'll right the rest as the NX comes out. For me, I'm just excited about the prospect of something new for Nintendo since the Wii U has gotten so little support.
I don't think they'll ever be mega-champions again of the industry. Sony has a dead lock on that. But the Wii U (and every Nintendo console before that) shows that their games are amazing. They just need a powerful, enticing machine to bring some 3rd parties back and sell enough consoles to be profitable. I'm fine with them being the niche machine that gamers have as their second console. I think Nintendo gamers are just excited about the potential, not totally confident it's going to kick ass.
Side note: You said Wii U is a financial failure, but is that really true? A commercial failure, but not financial as far as I've been able to tell. It's been making a profit for about a year now, I think. (I should probably cite a source here, but I'm too lazy).
It'll be awhile before I figure out how to do one of these. :P
