Lately I've seen many papers (for example "The galileon as a local modification of gravity"; 292 total hits on the arXiv) on types of field theories known as Galileons, and I'm wondering what the motivation for studying them is. I often hear of them in the context of "well-behaved" IR modifications of general relativity. For example, Galileons are known to arise from brane-localised theories of gravity as well as ghost-free massive gravity, which are themselves IR modifications of general relativity.
I understand that it is attractive to understand possible IR modifications of gravity for cosmological purposes (in particular, dark energy). My question is this: aside from being (or perhaps being closely related to) an IR modification of gravity (in general), what attractive feature do Galileons possess? Do they modify the IR of gravity in a way that could account for dark energy? Is it too early in the study of Galileons to tell?