Apparently I was on a real language-design tear in April, too - here's a post on probabilistic programming languages, proposing semantic primitives for, well, probabilistic programming. Where do DSLs stop and plain old programming languages start? ... Good question.
I have to say, the BUGS language [that was to the old WinBUGS: here's OpenBUGS, the current project] looks pretty darned interesting - you're really using this to set up a model in a declarative manner, then invoking an engine that writes the "query results" into the original file, looks like. I really like the cut of that jib.
Then there's Church. Wow. I think this might have Hofstadterian implications, honestly.