Here is a key quote:

Human brains are smart mainly by containing many powerful not-fully-general modules, and using many modules to do each task. These modules would not work well in all possible universes, but they often do in ours - See more at: http://www.overcomingbias.com/2014/07/limits-on-generality.html#sthash.S1KygaG4.dpuf

It is true that adult human brains are built out of many domain specific modules, but these modules develop via a very general universal learning system. The neuroscientific evidence directly contradicts the evolved modularity hypothesis, which hanson appears to be heavily influenced by. That being said, his points about AI progress being driven by a large number of mostly independent advances still carries through.

Hanson's general analysis of the economics of AGI takeoff seem pretty sound - even if it is much more likely that neuro-AGI precedes ems.