- last post: 01.01.0001 12:00 AM PDT
good question. i too was wondering the same. if you rewatch the campaign vid, at the point where the AI updates your PDA (allowing you to see a map of NM), you'll notice, off to the left, an icon of a red block which indicates the location of 'locked doors' on your map.
which leaves me to assume that your party of friends (co-oped in the same game) will be constrained to stay within wider and wider realms as the game progresses. Each 'realm', i'm assuming, will enable a new part of the story. in this way the game is both open world and linear. also, in this way, everyone would see/play a part in the same flashback.
[Edited on 06.09.2009 11:43 AM PDT]