STM in Pugs
Pugs (the Perl6 implementation in Haskell) has started to add STM, Ã la Haskell. Audrey says they're missing certain combinators, which sound to me like nearly all of the necessary ones, but still it sounds like they "get it." Audrey also hints that STM may be part of the standard concurrency model for Perl6 widely, and that some Summer of Code project is working on adding STM to Parrot.
I'll be pretty interested to see how all this pans out.