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.
Command
Royal Court (0-1 per Reclamation Legion)
*1 Overlord/ Imotekh
*1-3 Lords
*1-3 Crypteks
Core
Reclamation Legion 1+
*1 Overlord
*0-2 Lychguard
*1-4 Immortals
*2-8 Necron Warriors
*1-3 Tomb Blades
*0-3 Monoliths
Auxiliary 1-10 choices per Reclamation Legion
Destroyer Cult
*Destroyer Lord
*3 Destroyers
*0-1 Heavy Destroyers
Judicator Battalion
*1 Triarch Stalkers
*2 Triarch Praetorians
Annihilation Nexus
*2 Annihilation Barges
*1 Doomsday Ark
Flayed Ones
*1 Flayed Ones
Deathmarks
*1 Deathmarks
Canoptek Harvest
*1 Canoptek Spyder
*1 Canoptek Wraiths
*1 Canoptek Scarabs
Star-God
*1 C'tan Shard of the Deceiver, Nightbringer, Transcedent C'tan, or Tesseract Vault
Living Tomb
*1 Obelisk
*0-2 Monoliths
Deathbringer Flight
* 2-4 Doom Scythes