When they mean we create a combo I think they mean just one combo....as in item 1 + item 2 = item 3 not in the sense where you keep combining items after the first combination and result. I also don't think we'll have any 3 item combo before creating something so I doubt we'll see anything like item 1 + item 2 + item 3 = item 4.
Lol, I can just see the implementation of the old EverQuest crafting system and the never ending combining of stuff till you actually make anything.
Though I know that is not their intent, it's still a frightening thought.