There's a few possibilities here. The most obvious is that this is somehow related to the Stormwind repairs mentioned last month on Twitter by Cory Stockton. After all, if you're going to fix a park, druid intervention sounds like a good plan, right? The other option is that this is somehow related to Draenor -- and those wild vines have the look of some of the savage greenery found on Draenor, while the tents have the same purple color as used by some of the orc clans. This seems sort of unlikely at this point, largely because there is no Orgrimmar counterpart.
While we don't know what exactly the portal is for, it's still cool to see additions and changes being made to Azeroth right alongside all the gorgeous new vistas and scenery we're checking out on Draenor. We'll have to wait and see what kind of NPC's pop up around the portal, or how exactly it's implemented as more beta builds are released. But for now, those hoping that this might be some sign of a future full-out Emerald Dream expansion -- I wouldn't hold your breath.