Just few "rumors" I've heard through the "grapevine"...
*Tomb Kings/Princes mounts: Will be able to FINALLY ride a Skeletal Steed! Also strange rumor of an "old style" Carrion mount...
*New Character: Supposedly a "Construct" type, much like an Ushabti or the such! Only Hero level...
*Sphinx: Rules and sculpts aren't easy. But, if it happens, it'll take up a Rare slot, have Anti-Magic rules, and be more "defensive" then the Bone Giant.
*Ushabti: Upgrades such as Champs, and weaponary were mentioned...
*Bone Giants: Equipment/weaponary upgrades almost a definite! Sprue suppose to be well "furbished".
*Casket of Souls: No longer will take up a Rare...and optional rule to Target one enemy unit, and roll 3d6 vs their LD! I'm hoping this is incorrect...
*Curse: Killing a King will be more painful then a Prince, and not sure it'll have anything to do with LD tests...
*Tomb Swarms: No longer 0-1 of course...
*Tomb Guard: Optional weapon upgrades, Halberds with hvy Armor? Doesn't quite make sense...but who knows...
*Magical Items: Old style of Banner of the Hidden Dead/Legion will be back! Around 125pts, but will allow you to take any point sized unit (from set units) and have them appear at the START OF THE TURN!!! Thus a Charge will be available to the unit...coupled with Ikon of Rakaph, this is potentially the "one hit wonder". Much better Talismans and Arcane Items, some Weapons, Armor will probably stay much as is.
*Icon Bearer: Will get a "My Will Be Done..." Rule, but only affects Movement I believe...and an increase in his stats! (Wight King?)