If there is support for Groovy, Pyhton, [or whatever] continuations, I personally don't care because it doesn't make a real difference (languages are a matter of taste ...) and I don't think we should spread our energy over different Flowscript interpreter implementations which have to be maintained.
Well, we actually have to maintain a non-current forked version of Rhino (even if pretty stable actually), so I'd much rather change my taste (I quite like Javascript flow actually) if that buys me a more hassle-free continuation engine.
Ciao,
-- Gianugo Rabellino