Since the nether currently sucks and Notch will eventually add more nether content.
Does anyone know a way to delete the existing files for the nether without deleting the overworld. So the next time i go through a portal (after an update to the nether) it will generate a new nether world? Saving me and anyone else who does this from having to trek across hostile, lava covered terrain with jellyfish throwing explosives at you to get new chunks to load.
If you want to rig this a bit, you could generate a new world, and explore it's nether. If you like it, copy the DIM-1 folder from the newly generated world and place into the world you want to play on. On a similar note, if you want something kind of funky, you can directly take the files from the "real world" part of a world and place them into the DIM-1 folder. The result is that you have the "real world" as your nether destination.
But as for this process, there really isn't a quick way to do it without hacking. =/