Well, it will call for evolution in the ethical system. It's not an excuse to not simulate "brains" or build artificially intelligent systems.
How are you going to prevent abuse? I understand all innovations have risk, but I think the potential for abuse is so incredibly bad, that it's not even worth going in this direction. Assuming there's any way to stop it, but there's no sense in not trying either.
In any case, the current proposal is mostly a funding grab, you won't see an actual brain simulation come out of it. Even a nematode worm is ambitious right now. See http://www.openworm.org/
I accept that's a consequentialist argument though. If we did manage to create cheap, easy to run brain simulations, I think we're starting to run into the question of the nature of personhood and the nature of consciousness (something I hope to contribute to some day). Do AIs deserve to be free from slavery if they are not experiencing anything consciously but still have desires and creativity and can convincingly pretend that they do experience something (which a good simulation would do)? I have a feeling that regardless of the "correct" answer to that question, whatever it is, human beings' emotions are very hackable and we'll grant them rights based on emotional appeals if they get to that point. ;)
That would open an interesting technical issue though. If a human simulation was cheap and easy to run, and we wanted to legislate the conditions under which it was run (e.g. must be given reasonable sensory inputs and have hunger, sexual desire, and other wants set to near 0), we'll run into the DRM / TPM debate again, but this time with serious "life or death" consequences.