In 20 years people won't understand CDs either, or why people would carry around plastic as big as 3 iPods to play 12 songs.
Look at remote places in Canada or Australia.
Local data caching is important.
If you can get a cell signal, you can get streaming media, or at least you will be able to. I don't see that being much of a problem.
edit: And given trends in solid-state drives, local storage will be cheaper and more energy efficient than a wireless network for a long time.
Bandwidth (in the sense intended here) is measured in bits/second: how do you measure that from a station wagon [full of mag tapes]?
Now a freeway full of station wagons ... that has bandwidth.
edit: I always understood the quote as "the [potential] bandwidth"- the bandwidth that can be available using the station wagon as physical infrastructure.
And secondly, you just measured latency there, not bandwidth.
That's 1 hr latency, unless I'm mistaken. Latency doesn't include disk operations on the client side, does it? Is latency time between a signal being sent and received, or between sent, received, and acknowledgement sent/received?
ie, is latency time(client->SYN->server->SYNACK->client->ACK->server), or time(client->SYN->server)?
At some point, though, you get diminishing returns. If all you're doing is playing mp3s at 192 kbit/s, existing wireless is fine and future wireless will be more than adequate. There's no need to add the expense of putting local storage on a mobile device if you can achieve the same end cheaper with cloud hosting.
Now, this is all academic, as we're talking about a radio, and I don't think they're likely to be around by then. Whether or not a device includes local storage will be an economic decision given its intended usage and market conditions of the time, which nobody can predict with great certainty.