Brian Goetz has writes quite a bit about ongoing projects. The latest article he has done about pattern matching is I think http://cr.openjdk.java.net/~briangoetz/amber/pattern-match.h.... There is a load of stuff in there about destructuring patterns from about half way down.
Thanks, a methodical article! Not keen on special support required for destructuring. Nice that they discuss Visitor pattern (and the switch example for such cases looks nice). They don't dicuss double dispatch - but not relevant to them.
