Well, WiMax in a city will probably only get you anywhere from 1 to 3 miles. But supposedly it should be able to do anything that you can do now from any other network connection (WiFi, 10Base-T, etc.)
So if you can do it from ethernet, then I guess it would be possible...
Note, though, that any accesses to the disk would be extremely slow - and the connection would be slower as more people use the bandwidth at the same time...
Sorry I'm not familiar with LiveCD or the new WDS from Maxtor/Linksys. I think that this is more for read/write, though.
Not sure what you're planning on here, but if you have a small embedded linux product that needs to load a small kernel into local memory - of course you can grad the kernel by using WiMax. But you could just as easily grab it through a cellphone network (GSM, etc.) that has data services to any IP address.