a few months back a screenshot was shown at the pokémon game show that alluded to this game. Many people thought it was likely a pokémon fighting game, but I had hoped it would be an HD remake of Pokémon Stadium. Obviously, I was wrong. So far, it's unknown if pokémon that are not fighting type will be included or not. The only confirmed fighters are Lucario (and Mega Lucario), Machamp, and Blaziken.
Not everything about this announcement is disappointing, though. In fact, the main thing to focus on with any game should be "is it fun"? After watching what appears to be in game footage, I could see it being fun for people who are fans of the pokémon games and the fighting game genre. If you aren't that big into fighting games though, I'd stick to Smash Bros. This game will likely be of a more serious fighting game by comparison. Also, the idea to work with Bandai Namco to collaborate to make this game makes me hopeful for the future. Maybe they'll collaborate with Blizzard to make the MMO people are always whining about.