Personally I can't afford VR right now. The girls spend most of thier time in the chains when I play so I never really felt the need to sit down in the game. But I could see this type of feature being beneficial to those who do have VR. It would certainly add another level of immersion.
Also, 4.0 is on its way... We have some info about 4.0, but not too much about the new engine besides it's going to be more stable and able to handle much larger environments then the rooms were used to.
It's very possible they're added to the gameplay mechanics... I'd even say it's highly likely they did. In the first version you couldn't really grab the girls and move them around like you can in 3.5. A small but massively effective improvement. Also they added an auto forward thing that works like a hump when used right, the girls actually fuck and suck back in this version as well. Considering the Xmoon devs strive to create a real world feel within this game, making the player more versatile is definitely something on their list already.
Honestly this is the best sex sim I've ever played... and I'm pretty sure I've played close to all of them ever made by now. I'd happily be placed in a induced coma and tell the doctors to wake me up when XSP 9.9 comes out.