If you refer to the last Annual Results MAG are making a lot of money from car parking. Use of aircraft stands for valet parked vehicles will mean a lot of income for little investment, and is reversible for 2014 if necessary.
The problems will start when outbound flights are delayed for any reason and there are no remotes available, the taxiway system will quickly become gridlocked.
Personally I am not a fan of this idea as I think the risks are too great but if I was a beancounter...