Hasbro Toy Shop has listed the SDCC 6" Jabba The Hutt for order! Good luck scoring one while you can, but keep checking the link as more will inevitably become available over time.
UPDATE: And just like that, SOLD OUT! Hope those who wanted one were able to get one in that hour of availablity.
UPDATE 2: He's back in-stock! Grab one while you can!
UPDATE 3: And he's out of stock again. Lasted almost two hours that time.