I am legend- the sequel

I read that there going to be a sequel for I am legend. This is one of the very few movies I liked lately. I hope they won't f... this for me by doing something crazy artificial that I will have to pretend to buy just for the sake of seeing the sequel. I mean, the leading actor seemed to die at the end. The bunch of "whatever those were" were attacking him and he threw a grenade towards them. How are the writers going to make him survive this?