Saw this last night/earlier this morning. I thought it was okay. It wasn't bad, but it was too dry, and aside from the (very few) action scenes, nothing about this movie was memorable.

And they gave Smith's son too much screentime. His acting was typical of a kid actor, so that didn't bother me, but the character itself was useless. We only needed to see him twice:

1) When his mom dropped him off with the neighbor at the very beginning
2) When he met Klaatu and tried to use him to bring his father back

Otherwise than that, he wasn't needed. We were probably "supposed" to love him, but I felt indifferent. He was just there.