Seeing that they say that you can play the DLC in any order you want too, will that mean that Christine's dialogue in Dead Money will be different if you played Old World Blues first? I mean if the starting point is the Drive-in near Nipton, you'll get there faster than to the abandoned BOS bunker if you follow the main storyline, so starting OWB earlier seems obvious. Besides it would be kinda weird if you start with that Dlc and have her act like you've met before, only to have her act like she just met you in DM.
UGH this again. Christine has NOT been confirmed to be in Old world Blues IN PERSON. It is most likely and FAR more probable that she and Ulysses will be in recordings. Also while the DLC CAN be played in any order im sure that OBsidian would allow you to get the maximum story possible out of them by playing them in the order in which they are released.