who cares if will smith is black? does the character have to be white? saying that tom cruise should play MLK, jr is dumb. It's an important part of MLK's persona that he was black. Why does the character in a remake of a movie that didnt even follow the original book that well have to be white?
As far as the Rock playing the dude from Walking Tall, it was meant more as a tribute or a continuation of the story than as a remake. When they talk about the previous sherriff dying in a car accident, they are referring to Pusser.
And as far as I, Robot being a bad remake, the tie-in to I, Robot was an aftrthought. The script was written and someone pointed out it was similar in concept to I, Robot so they added a few lines in order to make the tie-in. As an action movie on its own I, Robot is pretty good, as a movie based on I, Robot it sucks.