Here is some leaked information on new ways of organizing your Necrons according to this weekend's White Dwarf. With the new Codex coming up for Pre-Orders this weekend, this can shed some new light on some of the units and ways you will be fielding your Necrons very soon.
Please consider these rumors as we have not yet had anything officially announced.
via an anonymous source on Faeit 212
This is from the new White Dwarf.
The Decurion Detachment is a new way of organizing Necrons. Formations are broken down into three groups, Command, Core, and Auxiliary.
Royal Court (0-1 per Reclamation Legion)
*1 Overlord/ Imotekh
Reclamation Legion 1+
*2-8 Necron Warriors
*1-3 Tomb Blades
Auxiliary 1-10 choices per Reclamation Legion
*0-1 Heavy Destroyers
*1 Triarch Stalkers
*2 Triarch Praetorians
*2 Annihilation Barges
*1 Doomsday Ark
*1 Flayed Ones
*1 Canoptek Spyder
*1 Canoptek Wraiths
*1 Canoptek Scarabs
*1 C'tan Shard of the Deceiver, Nightbringer, Transcedent C'tan, or Tesseract Vault
* 2-4 Doom Scythes