Currently the options for mouse wheel movement (with or without an additional modifier key, alt, ctrl or shift) are:
  • zoom camera in/out
  • up/down party list
  • up/down enemy list
  • cycle fwd/bck alliance list
Could you add change hotbar next/prev (like the arrows around the number for the main row)?

Currently the only way I've figured out how to do something similar is with macros using '/hotbar change [next/previous/#] and to bind those to my mouse's fwd/bkwd thumb buttons.