The Necron Warriors LOOK new, but actually aren't. White Dwarf #46 has the conversion used to make these as well as an example of what the finished model looks like. I totally recommend doing this. One box of Immortals will give you enough bits to convert a full box of Warriors. Just make sure to make Tesla Immortals!
Lastly, I'm pretty excited about this new book, Devourer, coming out. It's nice to see some Black Library love where the Necrons aren't just moving targets for Space Marines. Supposedly this one will have some actual dialogue between the Mephrit Necrons and the Blood Angels. I'll be reading it soon and I'll post my thoughts.