There are a lot of problems with these laws. The main problem is that such an AI would be completely dominated by the first law. It would spend all it's time and resources in order to even slightly decrease the probability of a human coming to harm. Nothing else would matter in it's decision process since the first law has priority.
Second, how would you implement such laws in a real AI, especially the type they are building? This requires defining increasingly abstract concepts perfectly (what is "harm"? What is "human being"? What configuration of atoms is that? How do you define "configuration of atoms"? Etc.) And this is pretty much impossible to begin with in reinforcement learners, which is what is currently being worked on. All a reinforcement learner does is what it believes will get it a reward or avoid pain/punishment. Such an AI would just steal the reward button and run away with it, or try to manipulate you to press it more. It doesn't care about abstract goals like that.
Second, how would you implement such laws in a real AI, especially the type they are building? This requires defining increasingly abstract concepts perfectly (what is "harm"? What is "human being"? What configuration of atoms is that? How do you define "configuration of atoms"? Etc.) And this is pretty much impossible to begin with in reinforcement learners, which is what is currently being worked on. All a reinforcement learner does is what it believes will get it a reward or avoid pain/punishment. Such an AI would just steal the reward button and run away with it, or try to manipulate you to press it more. It doesn't care about abstract goals like that.