I have a little bit of skepticism about the pattern matching syntax, for similar reasons to those Larry expresses, and that Steve Dower mentioned on Discourse.

Basically, I agree matching/destructuring is a powerful idea. But I also wonder how much genuinely better it is than a library that does not require a language change. For example, I could create a library to allow this:

m = Matcher(arbitrary_expression)

if m.case("StringNode(s)"):

process_string(m.val)

elif m.case("[a, 5, 6, b]"):

process_two_free_vars(*m.values)

elif m.case("PairNone(a, b)"):

a, b = m.values

process_pair(a, b)

elif m.case("DictNode"):

foo = {key, process_node(child_node) for key, child_node in m.values.items()}

I don't disagree that the pattern mini-language looks nice as syntax. But there's nothing about that mini-language that couldn't be put in a library (with the caveat that patterns would need to be quoted in some way).

The dead increasingly dominate and strangle both the living and the
not-yet born. Vampiric capital and undead corporate persons abuse
the lives and control the thoughts of homo faber. Ideas, once born,
become abortifacients against new conceptions.