Bare in mind that you also need to somehow do a brain scan with enough resolution to map every single connection if you want something functional. Also, what are you going to do about the sensory inputs (sight, hearing, nervous system). I'm sure it can't be good for a person's sanity to suddenly get completely 100% disconnected from the world.
And while a 1:1 map of the brain would maybe be feasible to do at the moment or in a few years, but very expensive (although getting ever cheaper), it's kind of like the straw-man AI researcher's answer to everything : do a neural network, repeat training set and hope that it computes what we want. Trying to flaunt your lack of knowledge and trying clever ways to avoid solving the problem yourself is just asking for trouble in so many ways.
In the end, the point is that AI is a software problem. Adding hardware will allow you a more stupid approach in solving it, but effective solutions are those that matter most.
Imitating the brain may be a matter of having enough computation power to allow a simple method to work. It reminds me of NLP where it seems we are doing a full circle back to the simple methods like Naive Bayes as they are showing better results than complex methods with enough data.
And while a 1:1 map of the brain would maybe be feasible to do at the moment or in a few years, but very expensive (although getting ever cheaper), it's kind of like the straw-man AI researcher's answer to everything : do a neural network, repeat training set and hope that it computes what we want. Trying to flaunt your lack of knowledge and trying clever ways to avoid solving the problem yourself is just asking for trouble in so many ways.
In the end, the point is that AI is a software problem. Adding hardware will allow you a more stupid approach in solving it, but effective solutions are those that matter most.