www.serebii.net Two Pre-evos.
A Roselia pre-evo, which is meh. Grass/Posion
A Chansey Pre-evo, which we already knew about.
On to new ones completely.
New Electric, called Korinku. Class called Flash. Sort of Bear/dog style. Black, Blue and Yellow in colour.
New Normal, called Bippa. Class Round Mouse. Sort of Furry Rat. Brown colour.
New Rock type, Called Zugaidosu. Class Head Butting. Sort of Dinosaur, Blue, brown colour. Cool.
New Rock/Steel, called Tatetopusu. Class Shield. Sort of Dinosaur. Yellow, Brown in colour.
New Bug, called Minomucchi. Class Bagworm. Sort of Leaf. Green, Brown colour.
New Grass, called Masukippa. Class Flycatcher. Sort of Venus Fly trap. Green, red, and light green. Has Levitate as an ability.
As to other new. The Pearl and Diamond Legendaries are Steel/Dragon, and Water Dragon.