It's about what I expected, but I'm generally happy with it. I think making it super similar to the Switch in terms of visuals and name is boring, but that it's probably a good idea for them given what happened with the Wii U's name.
I'm not sure if this is a nitpick or an actual concern, but I'm upset they haven't changed the button layout on the joycons at all. The position of the + and - buttons is something I've only felt worse and worse about as the years go on, they feel uncomfortable and awkward to use, and have made me want to swap to a proper wired controller more and more. I don't think making the new joycons bigger or changing the colour or anything helps that issue I have with it.
Having a new Mario Kart is nice, finally! I've been wondering about what will happen to the series in the future for a while now, with Mario Kart 8 essentially being a 10 year old game now and feeling like the biggest baddest greatest game in the series. I think the new track looks neat, and I'm excited to follow news about a new Mario Kart game again.
Being confirmed to be backwards compatible with the Switch's library is also a huge boon on launch. I don't think I have a lot of thoughts because it doesn't feel like we were given a whole lot, but I'm very excited for the Direct in April and I'll have a lot more to say after that, I'm sure.
DK is very much like his movie model.
I never noticed this actually, I guess they're trying to push the success of the movies towards the games now or something? It makes sense especially for Mario Kart, given there was a whole section about that series in the movie, and how approachable it is as a party game.