One thing i would like to see is accelerometer controls. For games like f-zero x
The input-sdl plug-in recognizes "Android accelerometer" as a joystick, but it would need a profile added to InputAutoCfg.ini. It has 3 axes (x-axis, y-axis, and z-axis) and no buttons. It records the affect of gravity (so lying screen-up on a level surface would record analog input in the -z direction, tilted on its right side would record analog input in the +x direction, etc.).
Anyway, to get it working in the emulator, you'd just have to add a profile for it to InputAutoCfg.ini. If you're interested in working on that yourself, I can provide you a simple app that prints the accelerometer values to logcat, which you can use to determine the values to use for AnalogDeadzone and AnalogPeak (will require a bit of trial and error to get it right). If you can figure out a profile that works well, I'll add it later (after I make the plug-in configurable through the GUI, so it doesn't always use the accelerometer as a joystick every time).