It seems that the airport taxi monopoly has come into being as of yesterday. I was a little confused as to what I was supposed to do when I arrived this afternoon as there are now no taxis parked outside the terminal building, but there are a few yellowcoats around directing people back inside.
The taxi company now has a large office right by arrivals where you pay a fixed price for your trip in advance (enabling credit card payments which is a big plus) and you then get sent outside to the car park with your receipt to a designated driver.
The drivers were a little concerned the taxi company didn't have enough drivers for the peak hours and things were quite cahotic at the moment. However for my 1400 arrival it couldn't have been easier, I even paid the lowest taxi fare I've ever paid for my journey in 3 years of doing it! I'm not sure what mechanisms are in place to ensure the taxi company doesn't abuse its monopoly to rip people off though, apparently they have a 5 year deal with the airport!