I'll probably avoid this topic like the plague after the japanese version comes out. But for the moment...
I'm excited for this game. It's a Kirby game and I've enjoyed most of them. Looks like this time around Meta Knight has a role in this, as well as a new character called Susie.
The US website has mentioned 3 new copy abilities: Doctor, Poison and ESP. It also comments on 2 new modes besides the multiplayer subgame Team Kirby Clash: Meta Knightmare Returns and Kirby 3D Rumble.
The Japanese website mentions you can add stickers to your robot.
Amiibo integration has a similar functionality to Rainbow Curse, where the tapped amiibo gives you an extra help through your journey: Smash Bros. characters such as Mario or Link will give Kirby the Fire and Sword abilities respectively. Tapping the Smash Kirby amiibo will give him the Smash Bros. copy ability, granting him the moveset from said game. In addition, the new Kirby line of amiibos: Kirby, Meta Knight, Dedede and Waddle Dee will give him an special treat. The three companions of Kirby grant a cosmetic feature of said character with the copy abilities Sword, Hammer or Parasol. The new Kirby amiibo, exclusively, gives the copy ability UFO, a classic power up from the old entries of the franchise.
All around, I've seen positive reactions from most people with just a few (crazy) exceptions.