I was too so so happy that she wasn't a potential after all. Throughout the episode watching I kept saying "I can't believe Joss would be so stupid, no one wants that to happen!"
I think it would have made a huge conflict between Buffy and Dawn. Because Dawn kept saying how much she doesn't care that Buffy was a slayer, and that she didn't deserve all she had just because she's a slayer. And I think Dawn WAS very jealous of Buffy. Even when she "found out" she was a potential she freaked out, but you can tell that she loved that "fact". She wanted to be a Slayer. Being noticed, powerful and not just the little sister. Maybe she even thought that that would get her friends and respect. No matter how much Dawn said she didn't care Buffy was a Slayer, no matter how much she said she was scared, she LOVED it! It was for a short while, but within that short while where she thought she was a potential, she felt that power. She felt like someone important. Now it will be her saving the world, getting many friends, boyfriends, popularity, etc. all that Buffy has.