Just a little one --
I guess since 4.1 there is a huge door behind the Blackstone Span which separates the daily quest area (north) from the battle area. You can't access the battle area as a the losing faction through normal means, however, if you BLINK as a mage I can confirm you can enter the battle area.
I think it is possible with duel/polymorph combo to trespass.
Greetings.
I hope this is no repost.