I would like to see a fully detailed Carrier Ops package, the FSX/Accel Mission stepped up about 10 notches. Day/night, good/bad weather, exotic locals, multiplayer tanker re-fueling and air ops, S&R, detailed carrier wing aircraft (fighters, tankers, helos, support aircraft, sub hunters etc.) and so on. (Being able to drive the ship w/VC Bridge gets a bonus Legacy Appreciation Point!)
An Alaskan Bush package in 5 Season Detail, multitudes of camps, remote strips, geographical realism with a customizable Virtual Bush Airline front-end. Fly multiplayer freight and passenger objectives within the larger context of managing in-game a virtual Bush Flight operation. In Alaska, modeled to photo real perfection, all of it.
European Regional Passenger Jet package. High fidelity aircraft, systems, ATC, and routes around Western Europe. Detailed urban areas and airports with photo real route scenery. Virtual Airline and ATC front-ends to round out a multiplayer aspect.
... and last but not least ...
An in-game, full featured, Voice Comm utility for online/social/Virtual Airline/ATC interaction.
These things are by no means "revolutionary", but they would be nice to see in Flight and would I imagine give a great many something to do.