The only thing I can think to add is that XML is pretty explicitly a rejection of an aspect of OO practice that Norm touches on only briefly: encapsulation. Everything accessible all the time is pretty clearly a hallmark of XML work. You can hide things if you want to, but it takes a lot more effort.
I’m pretty sure that Simon meant to say “data hiding” instead of encapsulation there, as the last sentence suggests. Encapsulation refers to the binding of associated data and behaviour into an identifiable whole. Data hiding refers to, well, hiding that data by not exposing it via the interface. There are many OO fanatics, myself included, who believe that you don’t need data hiding to be OO.
FWIW, I consider the Web to be the epitome of the anti-data-hiding view; resources as objects, URIs as object identifiers, GET as “give me your data”, POST as “process this data”, etc..