Just watched this.. have to say that it's a bit of a disappointment.
None of the menace of the original is there, and they've made no effort to substitute for it either. Keanu Reeves' delivery is too alien, insofar as Klaatu, whilst being completely alien and having totally different thought-processes, should have a hidden passion for Humanity by the end of the film. Michael Rennie had this perfectly in the original, but in this version, Klaatu meant nothing to us.. it was almost as if he'd just flicked a coin and then thought "whatever, I'm going".
A wasted opportunity.