There is no dual wielding in the game. It may possibly get added at some point. I don't think it would make a huge difference, though;
You can remove spells for the players too, it would make not a huge difference for me.
I use dual-wield in fantasy games,
no wizardry and it would make the devellopment of the game easier.
Maybe you think the money from dual-wield fans are not enough for the cost of making DW in game, you can lack it.
D&D3.5 rules adapted for PC was the best.