I am a huge follower of Spielberg and I have enjoyed (most) of Will Smith's movies. I read I AM LEGEND and didn't think the book was all that great. A good read, but not that great. My brother thought so, too. The movie wasn't much better, either.
I know the talent of both these guys, but I don't know the source material at all. I live in a small town in Alaska so...I won't be able to go over the source material any time soon, but you can't knock Spielberg's work. He knows how to bring a gritty reality to a film and Smith can bring that emotion to the character.
I'll try and get to the comics and try to see the movie when I can before I pass any judgment, but in the mean time...lay off the hate until proven otherwise. You haven't seen what they've done...they haven't even written it yet. Give it time before you hate something. Have reason first. You can be unsure of it, that's fine...but hate and wanting to kill them for even thinking of doing this film? Now we can see who the nuts are and whose sane...