Does the Gunzerker get to attack the turn they activate Gunzerking?

Yes. The action skill should read: Gunzerker gains the abilitity to wield 2 equipped Guns at once for 2 Turns. Each Turn the Gunzerker gets a Ranged Attack with both Guns at a single Target. While Gunzerking, Gunzerker gains Health Regen (even if they have taken damage this Turn).