In Chosen, Buffy, with the help of Willow, turns Slayer mythology on it’s head. They give the power of the Slayer to every potential in the world, rather than to one girl at a time. Female empowerment has been the predominant theme during the show (if you didn’t get that already, where have you been?). In Chosen, Buffy criticises the ‘old men’ who created the ‘one Slayer’ rule and says that Willow is powerful enough to overturn their decision. The possibilities are now endless - but for our Slayer it means one thing: she’s no longer on her own. A strong theme running throughout the seven seasons of the show has been that Buffy’s ‘gift’ sets her apart from every other person on the planet (apart from Faith, and Kendra of course), making a ‘normal life’ almost impossible. Now however, she is merely part of a great collective of empowered female solidarity and her smile at the end shows her realisation that all has changed.
The repercussions of Buffy and Willow’s act can be seen in the Angel episode Damage, in which a disturbed girl is given Slayer powers.