Though I'm pro-Python on maintainability grounds, there's one Lispish feature Ruby has that I wish were available in Python, that's not even in the Py3000 spec:

Though I'm pro-Python on maintainability grounds, there's one Lispish feature Ruby has that I wish were available in Python, that's not even in the Py3000 spec: continuations. The Ruby community doesn't seem to be too enthusiastic about using them though. We're just beginning to see continuation-based web framework experiments on Ruby, in the spirit of Seaside in Smalltalk. The continuation-based web frameworks make state management on the server transparent; but they have a scalability problem since state can't move between servers or even be taken out of memory on the same server. Now once somebody makes serializable continuations practical - certainly a hard problem - it would be a jolt to web development on at least the same that Rails has been.