Think Dastardly is refering to the two LW arena's - as in Dual. Given the increase in cap to 400 during the off peak hours (which really helps those of us in Europe etc), think he wants 1 arena shut to push everyone playing in off peak into a single arena, rather than having them both up and running.
Personally, I dont have an opinion on that bit - dont worry which one I end up fighting in. That said, more people on makes for finding a fight a lot quicker!
Wurzel