The Huskar Social Union wrote:The Warhammer 40,000 Launch Party Preview
So far they have shown off:
New Codexes for Space Marines and Necrons
New Primaris Grav Tank called the Gladiator (basically the predator but floats)
New Necron Monolith model
New Sister of Battle miniature called a Palatine
Teases of new Ork, Mechanicus and Dark Eldar Miniatures (seems to be one each according to the short video)
The Dark Eldar one is Lelith Hesperax, getting an Ynnari update.