I´m not sure, but I think Ethan is alive, 'cause I´ve seen a picture that shows Ethan fighting with Locke and I can´t remember a fight between them... Or this pic is from a cutted scene !?! But that's not the only reason, why I think he's alive. Ethan has such an enourmes power, that I can't imagine he can be killed so "easy" ( I know, a few shots from a gun are not really easy, but anyway...) And also there are so many unansewered questions about him. But maybe these questions will be answered in season two, in an other way. ( In Germany we're still at season 1 )
But if Ethan is alive, poor Charlie...