UPDATE: Two years later, in January 2006, the iPhone was launched. Wifi included, and much more. Development took 2 1/2 years so I failed to predict both the development and launch. This should reshape another industry, if it opens up unlike prior mobile platforms.
My Netgear hotspot crapped out on me prompting a new purchase. My Airport Express proved its worth while traveling, even serving as the emergency hotspot for a conference without wifi, but it lacks an out port for my LAN. When faced with the choice of new base stations, I must admit I went with the Airport Extreme Base Station -- because of their proprietary network overlays to extend range, print and play music.
I had tried to extend the range of my non-Apple base station with the Airport Express to no avail. Was worth the premium I paid to do so, and now I have extended range from the base station while playing iTunes to my stereo in the other room via Airport Express.
Apple's network effects work so well I am a hooked worm and want more. Russell thinks podcasting will move to mobile phones. Not that he is wrong, but Apple will not develop a phone. But I will eat my hat if they don't offer a wifi-enabled iPod to let you play directly to your Airport Express. You can sort of do this today, and there are hotspot directories you can load on the iPod plaform. Others bet this will happen too, but as a new-fangled remote.
Podjacking beyond FM will likely ensue. Like TV-B-Gone and bluejacking for bad music.
Update: Russell creatively thinks Apple will launch iPhone, but, again, they have network platform effects in wifi, so I would bet the above comes first. That is, until smart radios are a commodity and the software value add is a user experience of bridging networks.