It's looking like the 30k plastic stuff is pretty confirmed now. There's a Horus Heresy page up on GWs website (not linked yet, and content empty, but the page is there).
Thinking about it, they may be going with this as a core set now.
40k is still there, and still going fairly strong.
WFB is being .. rebooted I suppose .. and that's a risk. It may work, it may bomb.
The Hobbit movies have finished, so interest in that line is going to dwindle over time.
With the popularity of the 30k stuff on Forgeworld, could they be looking to transition it to a core line?