The delay is actually good news. They need to nail down the multiplayer fatal crash bug as if they don’t the game will be DOA. Also reports are floating about that the Eldar need to go back to the drawing board. I would not mind a few balance passes vetted by beta testers as well.
Necrons would be a whole other deal just like Orks or Eldar, but the developers have said that they would like to add further factions if the game takes off. I expect that IF extra factions are added, that Necron would be very high on the demand list.