not everyone will have the bandwidth available on their data plan to cover it if you are watching many games a week. so fox still holds some value for the time being + HD etc.
bandwidth however will be unmetered for telstra customers. (not telstra re-sellers like Kogan / Boost) I'd assume this would be the same if you are using wifi at home with bigpond.
reports are the app will cater for phones only for the first part of the season (so im guessing really basic quality stream), and they'll have a tablet version available by origin time (which would up the quality). you'll be able to buy a weekend pass, monthly pass or a season pass. So pretty handy if you are on the go. next year it is said they plan a PC version, that's the one that could be the fox killer for many people.
honestly, id imagine 9 will have some kind of say and unlike the AFL with every game live, i bet this turns out differently for the 9 broadcasted games and they still screw us around somehow.