If a west-coast sequel is ever made, I think it would be really interesting if it was based on an NCR civil war, The NCR has expanded too quickly, and not everyone in the new territories want them there. From Baha to Nevada to Oregon, territories are rebelling against the authority of Shady Sands. As Caesar's Legion still struggles with the fallout from the death of its talismanic leader two decades previously, the Brotherhood of Steel try to regain their power in the core region by any means necessary, and after outsmarting them all at the Battle of Hoover Dam, suspicions are mounting that Robert House is beginning to lust after more than just a technological playground in New Vegas. And into this powder keg walks a lonely traveller from beyond the borders of the NCR, outside the reach of Caesar's cohorts, and this one individual could have the power to change the future of the entire region forever... At my count, that's five different, interesting factions, allowing for a huge game world, loads of interesting and varied quests, and some unique play styles from each, from the technological brute-force approach of the Brotherhood of Steel, to the tough, hardy stealth masters of the NCR Rebels. I love the world Obsidian created in New Vegas, I love how it deals with people reclaiming a post-nuclear wasteland and dealing with all the challenges they face to put together a functioning world, instead of just blasting through enemies to reach an objective. And I'd love to see the series continue in that direction. There are plenty of games where you fight hordes of mutated enemies in claustrophobic ruins (and I've heard that S.T.A.L.K.E.R. does this far better than most). What the Fallout Series does is more or less unique in my experience.