Once again we have the opponents of the NBN trotting out what they think is the ultimate argument against the NBN - wireless. Buoyed by Obama's announcement of a nationwide wireless network and conveniently forgetting that the wireless solution is actually plan B (because the Plan A for a fiber network was stymied by conservatives in Congress), NBN opponents gleefully point out the number of wireless devices on the street as ultimate vindication of their wireless argument - see? Obama's doing it! See? Everyone has an iPhone! that's why wireless will obsolete the NBN!
The argument from wireless is spurious and anyone who has any understanding of technology knows it. But then this is not an argument for them, its an argument for the person on the street who probably owns and iPhone and wireless laptop and can't see why anyone would want to tether themselves to a fixed connection. It's like an argument that I used to hear constantly about broadband from users who didn't want to upgrade from dialup - "why would I need it? dialup is fine for what I do" (yes, this was back in the late 90's). People rarely see the need for change. However, conservatism aside, the NBN isn't about your iPhone or any of the other devices that you'd normally associate with computing, just like broadband wasn't just about faster email. There are plenty of fixed devices that will benefit from the NBN.
Your TV and Radio will need the NBN. On-demand digital media, such as Video-on-demand and music streaming-on-demand is a nascent market, which I suspect is on the verge of a rapid expansion (this is assuming that the content industry gets over itself and starts to think about a sustainable digital model for content delivery without their paranoia about copyright infringement). Wireless will never be able to handle the amount of digital media that people will use.
Already the streaming music segment of digital content delivery is beginning to grow and companies such as Sony are beginning to engage with digital content delivery models with their subscription music on demand services. This content will be delivered to mobile devices as well, but when your radio and TV are connected to the network digital content delivery will continue to expand, and with it the bandwidth requirements - requirements that would quickly overwhelm wireless capacity.
But digital media is not the only thing that access to reliable fixed broadband can enable.
Your smoke alarm will need NBN. Monitoring and alarm systems need a constant reliable connection, one that wireless will never be able to provide. Fire alarms in big office buildings use these sorts of connections and with access to cheap bandwidth there is no reason why these can't be extended to domestic uses - makes smoke alarms with cruddy 9V battery look a bit tame now.
And, yes, your dishwasher will need the NBN. Many devices in the home can become more functional with a connection to the network - eg. saving power and water by only drawing power or water when the tariff is at its cheapest. All of these things need reliable fixed broadband. Home automation systems too (lights, heating, etc.), will require access to reliable bandwidth.
All of these things that I have discussed are just the tip of the iceberg and focus merely on those things which the person in the street may see as a useful reason to get some "faster email".
There are of course many more sophisticated things that such an extensive network can deliver but the person on the street is still thinking about how interwebs is all about getting on to Facebook, so the lofty arguments about health, education, increased economic activity and the creation of new markets/technologies don't resonate. This is why the wireless argument is being repeated ad nauseum but it is the drivers of digital media on-demand services and increased convenience at home that will pique the interest of our person on the street just like access to YouTube and not tying up the phone line drove the adoption of broadband.
The NBN isn't just about your iPhone, its much broader than that. Wireless capacity is just not able to deliver in a way that is feasible for these types of uses - and unfortunately, due to some pesky things known as the Laws of Physics, it never will.