If this eventuates it will only be a win win situation for everyone concerned. The (large regional) city of Geelong, in addition to the western districts, certainly have the population to support such a move. And would likely support it in return. The savings to Jetstar are obvious. It's been a few years since I have been to AV but it might need a fair bit of cash spent, and work done pretty quickly to really support such a move in terms of pax facilities. Not that it would be much of a stumbling block for Fox. However as the majority of Melbourne's population is located on the east the vast majority of services will still need to go through Tullamarine.