Garchomp, Abomasnow, Drifloon, and Vespiquen as far as new ones go.
New evos; the two new Eevees, and Mismagius.
The starters are all pretty cool.
But 'sides from that- I find the lineup rather underwhelming. And of course, there's the fact that a quarter of the Gen 4 Pokémon are Legends. I actually don't have much beef with the Pokémon themselves- it's just that they all showed up at once. Couldn't they have spread them out over future generations?
The way it is now, you can field 2 entire teams out of 4th Gen Legends alone, and still have some left over.