I love the original and I thought the new one which I saw in Imax was actually quite good, a thoughtful reversion not a remake, well cast and acted, less interested in special effects, more in American liberal introspection at the end of the Bush era. Keanu Reeves is a good choice to play the Michael Rennie role, he looks and sounRAB convincing, I'm glad we didn't have some Kevin Spacey-type overacting it. The only trying bit is the obvious add on of a liberal box-ticking PC storyline about a white single mother with an increasingly alienated black step kid, but since both are good actors and there is a powerful and moving denouement to this storyline, they pull it off even though it's clunkingly unsubtle.
It's quite cool (in the British, not American sense of that word) and, like the original, will probably flop in America and do better in Europe as it is not a commercial, whizz-bang type movie and it's wholly critical of America's foreign policy, it's role in war technology and practice and in the US attitude to global warming and the environment. It's very subtle with its Christ-comparisons too, which the original was also, although the US censor had the original rewritten to include a statement that God exists. Thankfully, this film stays off the religious angle.
I love the dialogue scenes where the Kathy Bates character earnestly believes that America speaks for all humans and her President has to be dealt with and Klaatu is only interested in representatives of the whole human race and even then not much as he thinks little of humans who are the ones to be distrusted and disliked in this movie, not the aliens. The formidable automaton Gort is a wonderful recreation, evocative of the original, they'd never have designed him that way for a contemporary movie, but he looks fantastic. Shame he only makes a few appearances.
I agree with those who think the film slips away at the end. It needed one more final push to leave you thrilled, rather than merely contemplating what humans are capable of.