I think that Tribes/Quake III style weapon-changing would be useful, since it gets rid of q-q'ers (like me. ;o). I'm guessing that something would stop the weapon from being dequipped or changed during the "reload" state.
In Quake III, shoot a railgun and try to switch your weapon. It won't let you until it recharges. Same for Tribes 2. Shoot a spinfusor and switch your weapon. Same thing happens.