In general, is there a particular reason we don't see this more often in tooling for other (REPL-friendly) languages, outside of the Lisps? Admittedly I haven't spent a significant amount of time in the Python community lately (so not sure if this is common in Python tooling or not), but after becoming addicted to SLIME via Clojure, I'd have killed to be able to dump Ruby blocks from my editor straight to the REPL.
[0] http://pytools.codeplex.com/wikipage?title=Features%20Intera...