I think reliable blanket wireless coverage (which is what the cell phone providers are supposedly offering) is harder to realize than people think.

What are the overheads for yourself to provide a quality wi-fi enabled home. Your workplace, likewise, expends the effort to be a device hub. On-the-go data everywhere? It's likely more difficult than you think.

The cell-tower network was funded by everyone owning a mobile phone to exchange calls... data hungry devices are still in the minority. Apple could have rolled their own "A4" 3G network if feasible. It's in their DNA to control all the pipes. The fact that they haven't tells me that the pipes are prohibitively expensive.