Homo floresiensis, the so-called 'hobbits', have been redated from around 12k to around 50k years ago. For those of us (Adrian) who just published articles based on the former date, that's a bit annoying. For everyone else, this possibly lines up the disappearance of H. floresiensis with the appearance of H. sapiens (which is suggestive...) and provides yet another reminder of how unstable dating can be... Here's the nature article, and here's a nice write-up in the guardian.