Looks great. The yoshi games have always had different pacing than many other side scrollers, and they also generally have a higher difficulty curve.
I'm not worried about the release date in the most part, I know it'll get here when it does. Same sort of thing with Zelda. It's disappointing that it's delayed but it won't ruiin my enjoyment for it when it gets here.
The game looks great.

It's very hard not to be hyped for such a cute looking game!

The aesthetics are clearly developed with children in mind. You don't make a game based on baby dinosaurs made of yarn if you're trying to attract anyone over 12. I mean, think about it. 

As for the difficulty, Contra Hard Corps without save states... now that's difficult. Getting 100% on Super Meat Boy, that's difficult. Beating Yoshi, no matter the mode, will NOT be difficult. It will only be challening if you're using the regular mode as a reference point.

There is no reason adults cannot enjoy its aesthetics. As 26 year old man, I find them very appealing.

So you're going to play it on the casual mode? The original Yoshi's Island was quite difficult especially when getting 100%,  you couldn't afford to even get hit and the extra levels were some of the hardest in platforming, if you play it on casual then it's no fault of the game.

There's no reason anyone can't enjoy it no. I'm not arguing that. I'm simply suggesting that it's aesthetics are not aimed at the demograph you and I are in. I honestly don't think these games are made for us... even if we play and/or enjoy them.

I echo Curl's sentiments completely and I found the trailer very encouraging too.

I actually don't think it is aimed directly at children, I think it is meant to be age agnostic, equally able to appeal to children and adults.

For me i dont think any 2D platformer or platformer in general can surpass DKC:TF, the game is amazing to me, the music, level design and challenge is all there, i honestly think it will finish as one of my favourite, If not my favourite games this generation, but i think this game will be fantastic in its own right, the more platformers the better for me, bring more of them on.

It's aimed at diehard Nintendo fans who swallow almost anything with Nintendo's seal of quality on it. Not saying that's a bad thing though, but considering the sales of the WII U, you can't make money on games fir specific demographics.