I just think (personally) for sure there will be a Tempest II or Drum machine like Product from DSI, we have all bitten the Apple
Though we can't guess when ..
Tempest was and still is a complete Beast for the people that studied it. Its still ahead of its time.
as a personal taste, mostly just more memory to create thousands of sounds and Projects (or External SD card possibility). A couple of tweaks from the previous and that's it !!!
Even though some features people already mentioned will be good too.
FX for all channels , Polyphony and Polyrhythm to name a few
i even got a 2nd Tempest and no regrets .. its amazing how both interact with each other.