In Torchlight you can wield any two one-handed weapons. There is a Dual Wielding talent that adds damage when wielding two weapons, but what happens when dual wielding without the talent? Does it simply alternate back and forth? If the weapons are exactly the same, is there any DPS benefit? How does it work with one melee and one ranged weapon?
The only effect of the dual wielding talent in Torchlight is to increase the damage done while dual wielding - the act of using a weapon in each hand, itself, is unrelated.
If you have two melee weapons, you will alternate back and forth on your attacks. If you have a melee weapon and a ranged weapon, you will only swap to the melee weapon if you are within range, otherwise you will exclusively use the ranged weapon.