No clue if this counts as an exploit, but i will give it a go.
This will grant the ability to see somebody from a other server on you minimap, even if you are on a other server!
You have to use the new "Dungeon Finder" and complate a Dungeon.
Then somebody have to summon a portal, accept it and you will see the people in the current party (Crossrealms aswell) at your minimap.
Provided screenshot:
Yfrog - wowri