The language and platform I've hitched my developer career to was used in at least one DARPA-challenge vehicle! Complete with memory leaks and everything. And let me tell you, in a managed language that's no small feat!
Personally, I haven't had much use for the listener pattern yet. But I'm sure it's just a matter of time. I'll most likely make more use of it as I branch out of web-only development.
Yeah, it's a glorified advertisement. But whaddayagonnado? Hey, it's my website. I'll write about what I want!