One thing is certain... DSI needs to do something new next time because they have a new powerful analog synth now (REV2)... they have a powerful hybrid too (P12)... they have two boutique 6voice analogs too, and even a monosynth hybrid... as Dave is only doing BIG synths now (leaving the small ones for Pioneer obviously), he will need to come out with something different or things will start to overlap too much.
One of the most obvious routes and stuff he's missing on the inventory is something that utilize sampling technology in one way or another.... I've seen MANY people in here, come with "+1" when this has been talked about earlier, and I'm sure he's lurking us over the shoulders, if not by his employees if he's too messed up in the cellar "stirring the cauldron" for us all.
My intuition tells me we WILL se such a thing at some point... it is also a niche instrument that has no counterpart on the modern market.... a sampler synth with analog filters... there is no question it will be well received.
There could be other stuff too of course, but a sampling synthesizer made for performance would definitely hold it's own in DSI's range of devices... I certainly hope we will see one at some point.
And I would not be surprised if it is a modern version of his earlier Wavestation which was both popular, but also did crazy things with samples in it's time... it would definitely be the perfect name for a sampling synth, and with Dave's favoring of his earlier synths names, it would be plausible.... but only time will tell