In April 2013 the National Geographic magazine carried the cover title ‘Reviving extinct species, we can, but should we?’ suggesting that the technical challenges had been met, but some ethical concerns remained unresolved. Seven years later it is clear that this is not the case. Here we consider the technical scope, the uncertainties, and some of the bioethical issues raised by the future prospect of de-extinction. Biodiversity and welfare will not always align, and when a clash is unavoidable, a trade-off will be necessary, seeking the greatest overall value. De-extinction challenges our current conservation mind-set that seeks to preserve the species and population diversity that currently exists. But if we want to sustain and enhance a biodiverse natural world we might have to be forward looking and embrace the notion of bio-novelty by focussing more on ecosystem stability and resilience, rather than backward looking and seeking to try and recreate lost worlds.