Another piece of news that could be tacked onto this article is that while Team17 is handling the XBOne and PS4 ports of the game, Playtonic themselves are porting it to the Wii U because they want to ensure the Wii U will get the best and most polished version it possibly could

Source:
http://flip.it/j_7d3
That's good news, especially as the Wii U is rather underpowered compared to other current gen consoles and especially PC, the port needs extra effort put into it to be optimized enough to run well. I hate how so many console ports these days run at 30FPS and/or low resolution because they couldn't be arsed to optimize it for the platform. That's not only the case for Wii U but it's especially true for it.
i dont quite agree. huge n64 fanboy myself and devoured every rareware title back in the day, but this looks rather unpolished, uncharismatic and way too kiddy, considering they will be targeting an audience that has matured a lot but still loves this for nostalgic reasons.
i do however like the donkey kong style BGM/effects and hope they will add more of these minigames.
still, something seems off...
It's not perfect, but it looks like a lot of fun. The delay is not without reason, they're not going to release it until it's as polished as can be. The final version will be even better than what was shown in the trailer
To me the trailer is a confirmation that they really can pull off a platformer that captures the spirit of the early days of 3D platformers (not counting the ones that completely flopped *cough*Bubsy 3D*cough*), something that's hardly done anymore nowadays.
Visually there seems to be something missing, like they haven't had time to add in the last visual effects and finishing touches, but I expect that will be fixed by the time it's released.
I don't agree about it being too kiddy though. After all it is a spiritual successor to Banjo-Kazooie/Tooie, which many would consider "kiddy" (a term I honestly hate, because it gives people the wrong connotations), but that's part of the charm and if this was going to be a "grown-up" version of those games it just wouldn't be the same. It wouldn't have that Rare touch that sets them apart from the rest.