According to the PRD:
Offensive Defense** (Ex): When a rogue with this talent hits a creature with a melee attack that deals sneak attack damage, the rogue gains a +1 dodge bonus to AC for each sneak attack die rolled for 1 round.
Note that rogue talents marked with a double asterisk (**) in this list add effects to a rogue's sneak attack. Only one of these talents can be applied to an individual attack, and the decision must be made before the attack roll is made.
Now, Dodge bonuses stack with themselves, so let's say I had a Two-Weapon Fighting Rogue with a Sneak Attack of +5d6 who managed to hit a flanked foe twice in the same round (10d6 sneak attack total), does that mean that the Rogue gained a +10 Dodge bonus to his AC or a +5 Dodge bonus?
Also, as it reads, the Dodge bonus applies to all attacks that target the Rogue's AC, not only the those from the creature who took the sneak attack damage, correct?