I realized I never got back to you on this one. Sorry.
I was wrong on the way I expressed myself, so my assertion was incorrect. The point I was trying to make is that while retain cycles can happen with in a single class (like the example from my original post), they can al so happen with other classes: A retains B and B retains A.
Back to my original pitch, we currently prevent this with closures by using [weak self] or [unowned self], but we don't have a way to achieve the same with direct method references, which is a bummer.
Thanks