From their announcement:
Mantic have just put their Undead Warhost up for preorder on the webstore.
Containing all of the Undead plastic miniatures in one fantastically priced set, the Undead Warhost offers 52 miniatures and a warmachine, allowing you to start building the core of your massive Undead army.
With Skeletons, Revenants, Ghouls and a Balefire Catapult, you’ll get one of each Undead set, with plenty of variety and fun bits for conversions.
With the Elf Warhost as one of the most popular sets in the Mantic range, and we fully expect the Undead Warhost to follow suit, so make sure you visit the website and get your preorder in now.