The hard part I think, would be getting the licencing of all the different manufacturers. Mg and Yamaha are already emulated by you so you're part way there already.
As with the MMV2, we can't have everything running at the same time, (most things but not all) but we have a choice of modules... and thats the crux.
We might (for instance) want to start with say, 2 Oberhiem oscillators alongside a couple of Mg oscillators with perhaps Yamaha or Nord filters with EMS or Doepfer ring modulator etc.
They each have there own characters which give them there unique sound, but with mix and match capability, a whole new range of uniqueness would be achieved. There would still be the possibility of having 'blanks' in the unit and the GUI needs to be no bigger than the MMV2.
True modular in a fantastic, innovative and unique unit.
Thats my dream anyway, but then, I'm greedy for big boys toys.
Admittedly, I am no programmer and therefore have no real concept of the technical difficulties that may have to be overcome but I have faith in the talent of the guys at Arturia.
Go on... you know you want it, the question is, can you do it?
Think of it as a potencially highly profitable challenge that could blow your competitors out into orbit:D