In a new video on the social features of StarCraft II: Heart of the Swarm, community manager Kevin Johnson goes over many of the anticipated features included in the new expansion. Perhaps the most anticipated addition is the ability to play users in realms other than your own, which Mr. Johnson shows off in the video. Finally, I can get destroyed by people all over the world!
He also goes over the cleaner user interface, chat channels, and clan and group management. Clans are meant to be competitive groups, complete with a hardcore clan tag to add in front of your username. Groups, on the other hand, are somewhat casual -- they're more or less just players with common interests. Expect a Destructoid group as quick as possible!