Josh Abernathy of GitHub gave a presentation on the Reactive Cocoa framework last night at the CIDUG meeting. His way of describing the framework was a way to encapsulate and perform operations on a sequence of values over time. His UI demo using the framework was interesting, it was a bit hard to wrap the brain around in a quick demo setting, I would have to look at it again to try to understand and digest how it works and is beneficial over standard ways of doing UI operations.
BTW, today is the anniversary of the passing of Shawn Lane, who was an immensely talented guitar player. Any time you are feeling low, keep in mind that there are people who have gone through worse.