Hang on a minute before anyone steams in with both feet. I assume then there is not an issue of scarce resourses in which case just make another arena with a low cap please, maybe before we start telling anyone they are a fool FFS. Take it easy chaps 
Skuzzy has posted that the servers that are used for the game arenas have not hit 10% of their capacity, and this was back when the numbers were higher. No there isn't an issue with resources.
I don't think another arena is going to do anything. One large single arena WILL NOT happen again. HTC believes that it creates a "toxic environment" and stifles growth of his company. The problem with the game/arenas is the community. Until the community is pointed in a better direction you will have the issues most are complaining about.