This post will contain what to expect in the next updates. It won't include the normal bugfixes, only the main new features which are planned for the next major update:
Use of the new Navdata API that came with SU10
This feature has been now added as a "PUBLIC BETA" with the GSX October 17th Update.
New Fueling vehicles for airplanes with lower wings like the 737 or the MD80
There will be a completely new animation, with the refueling crew using the Fuel cable roller to connect to the airplane refueling point, not using a raised platform, but either a small ladder, or just by standing if the wing is low enough. Both Fuel Hydrants and Fuel Tankers will be updated with this new animation.
A proper VR/Dual Screen mode for the GSX menu
It will be possible to "pin" the menu, leaving it always open, which will be useful in VR or when undocking to a different monitor.
Ability to specify the Jetway floor height in the GSX Airport profile
The Jetway root floor height is data that doesn't exists in the SDK, it's only included in the GSX jetways and in a small internal database of 3rd party Jetway models. Currently, if a jetway model in a 3rd party scenery is not found in that database, GSX will use a default height of 4.60 meters from ground, which might result in passengers walking either too high or too low, if the actual floor is on a different height.
The update will add a Jetway tab page to the scenery customization dialog, where all different models found in a 3rd party scenery will be listed, so their height can be specified precisely, and saved in the airport profile. Only one number for each different Jetway model used by the scenery is required, not for every gate.