Wow, this trailer is getting LOVED by all the comic fans in my comic groups/boards. This is the only place I'm seeing a string of negativity.
Looked exciting as hell to me! I mean it's Superman vs. Batman, every DC fanboys dream-fight they want to see on the big-screen. And Doomsday!
As for Lex Luthor, it's because it's supposed to be young Lex. This is Lex Luthor year one, basically. In the comics, when he was young, Lex Luthor had a full head of red hair, and was a brash and arrogant scientist. It was his arrogance that caused a lab accident that left him bald, and was one of the character-defining moments that changed him.