Zvezda have just released their catalogue for 2018. Sadly on
the 15mm front things look pretty thin for the next year. No new releases for Cold War, whilst for WW2 there are 2 new releases due, both Russian.
One is the T-44 which was an obscure tank which never saw combat (not so useful) the other however is the SU-76 which as far as I'm aware hasn't been available in plastic in 15mm before and was a very common vehicle.