I know Terry posted about tactile feedback things that he thought would be nice, but I wanted to trim it down a bit. I'm just speaking to more basic cabinet hardware supported features specifically. Zen has always provided great support for this (and I would guess it's not going away as they have their own branded cabinets for sale). Things like multi-screen support for DMD and Backglass and direct table launch from cammand line options are awesome!
Camera views:
I think most people considered previous Zen FX2/3 releases to be more "games" and less "simulations". However looking to recreate actual pins changes that expectation. People are different heights and that has a pretty significant change on their 'perspective' when looking at a pinball machine. So what would be nice would be a couple options to pan around and save a couple custom camera viewpoints. More importantly is the ability to lock these down when playing, this especially includes not panning down to the plunger lane. This takes a player out of the immersion of a simulation.
Backbox support:
More of a question of if there will be plans to create some kind of animated/ROM controlled backglass support? If there was a title like Scared Stiff where part of the game is to "look up, stop the spider" with Cab support enabled, it would be nice if it could actually be displayed/working in a second window/screen (again because of losing immersion if the camera was to pan to the backbox on the main screen).
Audio:
Is there any way to support splitting the audio been "ROM" sounds and "hardware" sounds? Preferred would be supporting multiple sound devices with some surround support on each. But even something as simple as surround options with ROM sounds in the REAR and Hardware sounds in the FRONT would be a big improvement.
Controllers:
It would be great if there could be more support for the built in windows controllers interfaces. Having to run through third party software to get analog plunger and accelerometer nudging support is a bit of a pain and the x360ce software is tricky to 'dial in'.
-Mike