Elija's video of the very modern tram service looks to me like a perfect interim measure to service Melbourne's Tullamarine Airport by extension from Essendon of the existing service.
Not all air-travel passngers are in a 'rip tearing hurry' to get to and or, from the airport. Indeed, too and from Melbourne's airport on an 'iconic' Melbourne tram sounds good to me. Throw in Myki cheap ticketing that co-ordinates travel with the remainder of public transport options at reasonable prices, and that's all good.
The Skybus would remain a more expensive, express option, outside of peak road-traffic, congested periods.
All this as an interim measure prior to a dedicated faster train option at an indeterminate date post 2020.