More random conjecture for the rumour mill
Warhammer World have put up some new decorations in the museum. They are cabinet-sized backdrops that cover the mirrors at the back of the display cabinets. They are currently only in three cabinets - the Necrons, the Orks and the Tyranids.
Now this could be simply because they were the first printed, or they were done first because the cabinets are presently mostly empty (except the necron one). Or it could be because the schedule has 'nids first, Orks next.
You can make of this what you like, I'm just reporting what I saw today. I'd post the pic I took, but my phone hates Photobucket and I don't have desktop access at present.