We have no idea how neurons actually work.
We have no idea how brains actually work.
We have no idea what consciousness is, how it works, or even if it does exist.
If you do not know how a radio works or how a transistor works or what the knobs and dials actually do and cannot even build a simulation of how one might work you are in no danger of building the ultimate radio to rule all others.
Having a bad idea does not make you closer to having a good idea.
Recent article in The New Yorker:
http://www.newyorker.com/online/blogs/newsdesk/2012/11/ibm-brain-simulation-compass.html
Here is the research report from IBM, with the simple title "10^14":
http://www.modha.org/blog/SC12/RJ10502.pdf
It's nothing like a real brain simulation, of course, but illustrates that hardware to do this is getting very close.
There is likely to be quite a long overhang between the hardware and the software...