This will just be more connected realms. Each realm keeps its realm name & thus the characters on it keep theirs. All this does is make it where multiple realms will effectively function as one realm – they will share the AH & be able to trade and join each other’s guilds.
My server (Bloodscalp) & Boulderfist were the first ones to ever be connected. Shortly after, we had Dunemaul, Maiev, & Stonemaul join us as well.
If you wish to see the current connected realms list, it can be found here: