Is the + weapon damage% included in the displayed damage?
Any bonuses or modifiers that are gained from an affix on the weapon itself are already factored in to the items stats when you view it's tooltip.
Bonuses to +Damage or Attack speed on other items, such as rings and off-hands are not reflected in the tooltip of your weapon, but are factored in to the Damage stat on the character sheet.
Keep in mind however, that affixes such as + Damage and + Attack Speed, when found on a weapon, do not affect your other weapon if dual wielding. This includes the benefit of gems like Rubies.