Martin Geddes' opinion on net neutrality, followed by David Isenberg's response and Geddes' reworking, misses one element that I believe has something to do with it: choice of physical access medium.
There must be some sort of consensus about the undesirability of having the streets dug open all the time. Operators are supposed to share the local loop, at least in Europe. This will give ISPs the power to block if they wish (like Zen does in the UK). If you don't like the ISP's blocking or prioritising policies, you simply churn to another. That is why LLU is so important.
Now, of course the US is an entirely different market. Without the obligation to share, Ed Whitacre can dream of charging Google (as Geddes puts it). But here I agree with Isenberg. Users simply have very little choice, with cable not covering the whole nation and having no obligation to share either. So, net neutrality is preferable.
This may change, once BPL, BoS, WiMAX, 4G or BiG become ubiquitous. Only then should everybody owning a local loop be allowed to manage the network as he pleases. But BPL is not realistic as an access medium, as the FCC seems to be dreaming of.