A hobbit or a microcephalic homo sapiens?

Three years ago, archaeologists announced the discovery of what they consider to be a close parent of our species, Homo floresiensis. Floresiensis was supposed to be a small cousins of Homo sapiens. Now other researchers argue that it might be only a microcephalic humans. A paper in Trends in Ecology and Evolution discuss both arguments and show how this problem is related to the general problem of theories of brain evolution.