OK, so first off, I realize everything that we know about the NX is rumor and speculation. However, based on (what we think) we know about the NX, I'm definitely concerned, especially at the $299 price point, which I just honestly think is too high for what they are supposedly offering, and who they are supposedly marketing it towards. I'll try to look at this thing, based on what we've heard, from two different standpoints here.
First off, console gamers: Frankly, I think Nintendo lost the majority of the console market a long time ago, with Wii simply being a fluke. Every other console, including Wii U, has simply continued they're downwards sales trajectory, and there's a few reasons why I think NX won't be any different here. Firstly, this thing will NOT have the third party support of devs working on PS4/X1/PC, even if the NX can match those systems for power, and has a relatively normal controller. Third party devs need to see the console as a success, a sure thing, before they jump on board and invest in making games for it, but of course, the console needs their support to be successful in the first place, creating a cycle Nintendo hasn't been able to break from since the N64 days. That combined with the console seemingly being less powerful than the competition despite being the same price likely means it's dead in the water, at least as far as the console market is concerned. On the other hand...
The portable market:. OK, so the 3DS did pretty well, and based off the rumors we've heard, Nintendo will mainly be marketing this as their newest portable console. I think Nintendo could do well with a new portable, as there still seems to be a market for dedicated portables, and Nintendo has always dominated this market. However, there does NOT seem to be a market for powerful, expensive handhelds. If there was, the Vita would have been far more successful than it was. You could attribute this to the Vita lacking Nintendo's library of games, but the 3DS itself also really struggled until it was dropped to $199. People in the portable market just seem really hesitant to buy an expensive handheld, and they don't seem to care much about power either. If they did, they wouldn't still be buying 3DS systems with freaking 240p (!) screens in 2016. Going off all of that, it really doesn't seem like Nintendo can suceed here with such an expensive portable console, and I just really doubt that the 3DS's audience will care much about how powerful this thing is, or that they can play these games on their TV's (I doubt they'd be in the market for a portable if they did).
The only hope I think Nintendo's got right now, at that price point, is an amazing library of games. The idea of Nintendo consolidating their portable and console software output under one roof seems really promising, and is the main reason I'm excited for this thing. I'm just not sure it will be enough, honestly.