This particular publication may add new data, but this basic finding about London cabbies is years old - it won the Ig Nobel prize years ago. Not sure if the previous work was by the same research group or a different one.
No mention of that in the article, of course, because press-release science exists in a timeless vacuum independent of context or references.
The big advance here is that the current study shows that the brain change occurred directly as a result of the learning. Previous studies had a weakness in that they only looked at brain size well after the learning had occurred; raising the possibility that people with bigger hippocampi choose to become taxi drivers, or are the only people who pass the test.
So the new study established causation, extending our knowledge beyond the correlation.
No mention of that in the article, of course, because press-release science exists in a timeless vacuum independent of context or references.
EDIT: Not surprisingly, the folks at the Annals of Improbable Research are better science journalists than average: http://www.improbable.com/2011/12/09/taxi-driver-brains-a-fu...