The plan was to produce a spin-off series from TV hit Buffy The Vampire Slayer, featuring a number of superhero vampire slayers.
OH. SO WHAT WOULD HAVE HAPPENED?
The series would have featured a number of potential vampire slayers who were given super powers following the events of Buffy's finale 'Chosen'. The show presumably would have been set at a school where the newly powered slayers would have learnt how to deal with their new abilities. Alyson Hannigan may have reprised her role from Buffy The Vampire Slayer as witch Willow in a number of episodes.
BUT WHAT DID HAPPEN?
The pitch for the show was simply that - a pitch only. Buffy creator Joss Whedon shot down the idea pretty quickly as he felt it wouldn't work. In the grand scheme of things it just became one of a number of unproduced ideas for a Buffy spin-off, alongside Buffy: The Animated Series and Faith The Vampire Slayer.
WAS THIS SUCH A BAD THING? No, it was a great thing as Slayer School was a bad idea. The Potentials (as they were known in Buffy The Vampire Slayer) served a point in the story arc of Buffy's final season, but beyond that there never seemed enough material for a spin-off show. Some of the Potentials did feature again in Buffy spin-off comic Buffy: Season 8. BUT WHAT IF? Look, let's not dwell on it. It was a shit idea and it didn't happen.