I think a combonation but set in the same "space" like an MMO if its an earth based game ill use this example. Lets say when this game comes out there are only 6 playable areas they are all huge but there are only 6. the maps could be like future new york or L.A. etc. then some DLC of smaller areas like a new "dungeon" or multiplayer arena or new guns or new bosses etc. Then a whole new game thats actually an expansion pack that "opens up" 6 more playable areas like places in what used to be Europe or South America etc. thats my thoughts... Theyd probably do it a different way cause that would require downloading ALOT (all the new maps from the expansion pack) to your consoles HDD and then use first game disc to access it. I think they want to be able to do this style of small DLC then future "expansion packs" but theres the other possibility that its a Mass Effect esque game where its a completely new game and your save affects some things in the next game like any guns or armor you unlock gets passed over etc. So long story short... I have no idea but those are two thoughts I have on the matter XD p.s. thanks for reading this if you actual read this hahaha