Blizzard has detailed the upcoming StarCraft II patch 2.1 that targets clan players.
An in-game solution for scheduling events for groups and clans now exists, allowing club officers or owners to mark a date, title the event, set the duration, and provide a description all within StarCraft II. Groups are also able to create and upload a custom 255 x 255 club icon, which should get interesting. Some gamers tend to run wild with this kind of freedom of expression.
Going a step further, however, are clan decals. These are only usable by clans and previously showed up flat on the map in such a way that players were making decals that looked like units. Now, Blizzard will display them in-game as a floating icon (shown above).
The patch isn't finished yet, but it's up on the public test realm for testing.
Patch 2.1 Preview: Clan and Group Improvements [Battle.net]