To "encourage" player moving between the 2 wasteland more (and make it more meaningful), why don't we make some items that is only available in FO3 (or FNV) worth much more on the other side.
For example, customers in Ultra Lux are bored with steak, and so, after the "beyond the beef" quest, Ultra Lux will pay the courier 400 caps for every piece of Mireluk meat (and 600 caps for the soft shell mirelurk meat) as they don't have that in the west. On the other hand, those rich chaps in Tenpenny Tower may pay more for a bottle of Sunset because they are bored with Nuka (or, some drugs that is only available in NV, with loss in karma).
In that way, players will always have a reason to move between wastelands.
It will be great if we integrate a caravan mod or "mobile home mod" I mentioned on nexus
http://forums.nexusmods.com/index.php?/topic/1158768-a-mobile-camp-mod/
And if we change the train to a truck (if), we make add a meter bar just like the waiting or sleeping mod (NV on the left, capital wasteland on the right) and initiate random encounter/raid in between just like the Fallout1 (just load a big, featureless cell with enemies approaching from afar. Once the fight is finished, just "activitate" the train/truck to continue the journey).
May add some wildwest perk features like gorjila, or a nake maid statue on a water tank ;)




