I hope they include my fave Fighting-type line, the Riolu evolution line. Lucario is popular and a very strong attacker. I want a nice mix of 5th Gen Pokemon in there, but have at least a few lines from all past generations.
I'm also hoping for Aipom/Ambipom to make it back in there cos I love monkey-based Pokemon, and given my Chinese Zodiac sign it's fitting I want a monkey in there, otherwise I'd like to see the Pansage/sear/pour lines back too.
I know Eevee and all its other Eeveelutions are probably confirmed due to Sylveon, and maybe even the Pikachu family to a lesser extent since the trailer saw the player encountering a wild Pikachu.