I was just wondering why you couldnt access the trade channel or auction channel in the nether. Say maybe somoene wants to buy netherrack/glowstonne/soul sand via the trade channel, and someone goes off to harvest it in the nether. SInce the trade channel couldnt be heard in there, someone else may sell them the supplies without the person in the nether ever knowing until they came out to realise they wastes their time harvesting now uneeded supplies. I think it would just be useful to have the channels in there because you can easily get back to the actual world from the nether using /mvspawn, so theres not really a point to not being able to use the channels.
I wonder if it could be made so you can actually leave them while in the Nether, and obviously join them.. It's nice not having chat spam for selling stuff while in the Nether. o.o