First was his discussion about using lists as the basis for data structures. In Perl we have both lists and hashes, but the idea is the same, namely, flexible changeable structures that are easily evolved to cover the problem space. This way of building a program seems to work out rather well, at least to start with (to find the problem space and prove that it is even manageable, for example).
Check this paragraph from the essay out:
Arc tries to be a language that's dirty in the right ways. It tries not to forbid things, for example. Anywhere I found myself asking "should I allow people to...?" I tried always to say yes. This is not the sort of language that tries to save programmers from themselves.
Now replace "Arc" with "Perl".
So... anyone started the Arc-on-Parrot implementation yet?