An archaeologist who has spent decades studying sites in the Sahara says nomads who roamed the area millennia ago were the first to domesticate cattle.
At the time, what is now desert was a vast savannah with a humid climate, Dr. Stefan Kropelin of the University of Cologne told the BBC. When the climate changed and the area became one of the driest places on Earth, its inhabitants moved into the Nile Valley.
Still not sure what is "new" here, since Wendorf et al. have been arguing this for quite a while now, based in part on cattle remains found around desert playa lakes. They based this on several pieces of evidence, notably that cattle (Bos) bones were smaller than their wild counterparts and that the playa environment could not support cattle without the assistance of humans. This hasn't been universally accepted but it's been out there since the early 90s. For a mini-review and references see this paper by M. Brass, Tracing the origins of the Ancient Egyptian cattle cult:
Taken together, the two indications above suggest that the population which arrives in Nabta after 5,500 BC -- apparently pastoralists from the Sahara with a new and higher level of organizations -- influenced the developments in the nearby Nile Valley. Wendorf & Schild (1998:114) also hypothesize that the primary external stimulus for the rise of social complexity in Upper Egypt was contact with pastoralists of the Western Desert. (p.102)
Contrary to press reports, this newer work seems to be a refinement of the chronologies, rather than a brand new theory.
Wendorf, F. and R. Schild. Are the Early Holocene Cattle in the Eastern Sahara domestic or wild? Evolutionary Anthropology 3(4): 118-128