I think Bonnie will become something like Cade

Man I really hope so. Bonnie needs a happy ending more than anyone. I felt the same way about Matt until last night. I don't like how he treated Caroline.

Cade became what he is because he died at the release of his psychic scream. Bonnie is still alive. Becoming immortal now would just make her a powerless immortal unable to do anything like Cade. I hate that they are even calling Cade immortal. He's dead, he's not immortal because he's not really alive, he never said he was brought to life or even resurrected he only said he stepped through the portal and now is physical. I also find it strange that the most powerful telepath in the world doesn't know what they are planning.

Nemo Unus Animabus Carnem!

There was infact something like a energy blast (is that what it is called?) at the very last moment of the episode. So in the least we can say she becomes a badass witch. Being immortal would stop Elena from coming around, and that seems to be the point of the series anyhow :/