It is nice that he mentioned Light Table. I would not be surprised if Swift ends up really benefitting Clojure adoption indirectly. I think one of the big hangups for newcomers is that, if you don't have experience with a Lisp, it's often difficult to understand the benefits of interactive development. If a large amount of new programmers become exposed to it, they'll be more open to other options that provide simila…
The only thing that makes me sad is that because of their focus on secrecy, they're doomed to relearn all that we learned along the way. Having played with the swift playground stuff, just an hour long conversation could've made a big difference. Such is the way of Apple though.
An example of this is Go; they don't actually take input from outsiders (generics) and when they have had to give in to outside ideas they implement it poorly just to be different (exceptions as panic). They would rather people put in a no-op printf to avoid the unused package error rather than letting it be a warning because of their own self-righteousness.
Apple's secretive process may not be ideal, but there are far worse processes out there.