Of course Silas didn't heal Shane. Silas is evil, and with his plan to raise the veil between our world and The Other Side, he's brainwashing Bonnie. This can't happen. I mean, we all love Jeremy, Jenna, Vicki, etc but with one comes all. The tomb vampires, Kol, Finn, Esther, Mikael, and so forth. If we're lucky, the Hunter's curse will affect Silas once he's in his original body, because it's obviously not doing anything as Shane. But that kind of makes you wonder, if Silas isn't a witch, how does he look like Shane? Someone must have used magic, unless Shane is a part of his own doppelganger line. But didn't they say that Silas' eyes were blue? Shane's eyes are brown..
I'm now confusing myself.
Hasn't anyone thought about when Esther turned Alaric? She made it so the white-oak couldn't kill him. Instead, his life force was tied to Elena. The cure could have worked on Alaric too, but no one knew about it. But there is usually more than one way to kill a vampire. Silas' life force has to be tied to something. Sure, magic-overdose and the cure does the trick. But you know how these writers work. They're going to pull something unexpected.
I think it's going to be there, but not in the way they expect. Then they're going to do something wrong and BOOM! Silas is home. But I'm not sure. I'm hoping it's real, though. I just don't like Elena as a vampire, she's better as a human.