Once you ran out of ammo in Quake3 you were helpless. Something that made my day though was the return of the QTest out of ammo noise. I forgot to ask if it would remain this way.
Most people seem to enjoy the thought of a melee weapon as a last resort.
Location damage was removed completely. Hitting a guy in the head was a bit too random for a fast paced multiplayer game like Quake3 taking into consideration internet latency and other things. No damage skins as far as I could tell. There will be blood splattering and blast decals on walls in Quake3. They only had place holder decals in the game for blasts and no blood splattering at the time.