All it is is a glorified Disney Store with theme park merch. Nothing overly special aside from the awesome Walt Disney Studios shirts they have, I have two, one from 2006, one from 2008. What's odd is that it's operated by Walt Disney World, as opposed to Disney Store or Disneyland.
It is totally a little strange how the merch is WDW. Even the receipts say WDW on them.
And yeah. Disney Store + WDW merch + a little bit of studio-specific stuff (shirts, sweaters, pins, etc.). The Employee Store, on the other side of the Studio Store's building, has more of the fun Studio merch.