If we ask Ray what he means by "brain" we may understand better, the part of the brain that is practical to reverse engineer first is logic, or the neocortex. Assuming that Ray means the whole brain is where I think neuro-scientists are correct in their conclusion as of now 10 years is very optimistic. On the other hand if we only consider the logic center and don't deal with vision centers, speech and hearing centers, motor functions and autonomic systems, then we can probably do it. The key problem is input, the brain is nothing without data input and interaction, and experience.
There is more to the human brain then logic, but at this point raw compute power which is approximately 20 Quads per second and developing subroutines to simulate neuron function is what I think Ray is speaking of, simulating sensory stimulus response may be part of that program. The co-processing centers that pre-process the input to signals the brain as whole understands is another problem, and I don't think this is what Ray is predicting, but I think we need to ask him what he means before we jump all over his statement like we know what he's talking about. The brain is an electrochemical streaming massively parallel biological processor, which seems to be very well suited to pattern recognition and linear logic calculations. The brain not well suited to exponential logic, so neuro-scientists are correct from their frame of reference but wrong in the actual application of their logic because it's linear.
Raw compute power and the interactive subroutines which are repeated over and over in the wet wired world of the brain, simulating the plasticity and electronic logic is probable but the chemical side of things is a whole other issue, this would involve understanding hormonal function and interaction at a level not available today. It would require the understanding of calcium, potassium, sodium and other ion channels and other mineral interaction and function in the brain, and it would require the mapping of the two-way interaction between antagonists and receptors, re-uptake of hormones and their effects on signal processing.
Is what Ray Kurzweil says clear? On the surface yes, but the meaning of what he is saying needs to be explained and not so quickly dismissed.