eight new classes, with multi-classing options. There are some NEW multiclass option/strategies, too.
At least one new race that hasn't been published in any additional product.
Animal companions for Rangers, with adaptations for other classes.
Psionics? Don't know, but psionics is a power source like any other, if/when it comes out.
A *few* different Controller types. We'll see what that means...but very different approaches to the controller type, a new sort of game play (not new mechanics, just a very different feel for the controller.)
Martial Powers - two new Warlords paths, "resourceful" (based on Intelligence, even stronger on "control of the battlefield" mechanics) and "risk-taking" types.
Arcane Power Book - support for Swordmage from Forgotten Realms. No support for Artificers, tho.