I asked a similar question[1] of Arc many moons ago and received an interesting answer from pg[2] that I think applies:

    A lot of people seem to feel that a language 
    isn't real unless the designer is talking to 
    them every day. But that's not the only way 
    languages happen. Nor possibly the best way.[3] 
    I feel like you get better ideas if you think 
    in units of occasional essays rather than a 
    stream of tweets. It seems likely the same 
    will be true with language design.

Rich and Stuart Halloway have indeed been silent in the public forums recently, but I seriously doubt that they have stalled one iota.

[1]: http://blog.fogus.me/2009/02/06/yegge-clojure-arc-and-lolita...

[2]: http://news.ycombinator.com/item?id=470254

[3]: Hammock-driven development http://clojure.blip.tv/file/4457042/