Much of what he said will be familiar to those who have followed his speeches or read this piece for the London Review of Books. The thrust of it is that institutional systems (such as the banking system) can become locked into certain paths, which are self-reinforcing, and then very difficult to break out of. There is then a role for policy-makers in seeking to understand how such a system came about historically, in the hope of understanding how it might be disentangled. This piece of mine was partly influenced by what I'd read of Haldane.
A critique one might make of Haldane is that of all the traditions of heterodox economics that are out there, this one is the most politically inert (of course that's also what gives him the freedom to develop it, from a senior position within a central bank). It lets a lot of people off a lot of hooks. As he states in the interview, nobody deliberately rigged this system to work so badly; nobody takes bad decisions deliberately or for consciously bad reasons. But how true is this? What is going on when the City of London provides 51% of all Conservative Party funding?
I had more questions for Haldane than I was able to ask in the time available. But I now regret not asking him about lobbying, which is a conscious effort to leave a certain 'evolutionary equilibrium' intact, and prevent a new one arising. It seems that this effort to fuse the state and the economic status quo (focused on by Colin Crouch in his book) that is most problematic for Haldane's systems-evolutionary perspective.
Update: The Telegraph have covered the interview, suggesting - a little implausibly - that this interview might land Haldane in trouble with Mervyn King.