it's a good article. If you read it in conjunction with "succinctness is power" ~ http://www.paulgraham.com/power.html you can get another view on what parts of languages are useful & why.
'... working on Arc with Paul and if any of his ideas are making it in there ...'
Dont know. They both appear to be pretty busy on their own stuff.
Matt you made the comment on reddit, 'Arc "compiles" into Scheme' didn't you? ~ http://reddit.com/info/15gkq/comments/c15iof