If you're in the market for another PAX-based preview of Obsidian's Fallout: New Vegas, there's one awaiting your perusal over at Cheat Code Central.
Before I get into my personal experiences within the world of New Vegas, let's go over what changes Obsidian's made to the Bethesda's core Fallout 3 design. At first glance, there don't appear to be any; New Vegas looks, more or less, like it could be a western-themed expansion to the last Fallout game. Despite the visual similarities (the desert is actually much more colorful than the bombed-out Capitol wasteland, which was pretty much irradiated to the point of utter erosion everywhere), New Vegas actually has some new tricks up its sleeve to keep it from being more than just Fallout Heads West. For starters, there's a real story here; not that anyone probably played Fallout 3 for its basic narrative, but it's a nice touch that Obsidian is actually putting some thought into the fiction of New Vegas. Not that I saw any of this, but at the beginning, your character is essentially left for dead, and because of it, you have an actual objective when the game begins. V.A.T.S., the specific-body-part targeting system introduced in Fallout 3, has also been given an overhaul, which makes it both easier to use as well as more versatile; now you can target enemies with melee weapons, with expectedly gory results. The morality system has also received a facelift after the somewhat binary feel in the last game. Obsidian is promising there will be a lot more gray area with decisions now, and your actions may not have such clear-cut or one-sided consequences. There are also traits you can choose to take (or not take), which can affect the game, and who or what you encounter in different ways. Finally, weapons can now be tricked out with new parts and ammo types (likely a not-so-subtle nod to Borderlands) to achieve even more effective and deadly weapon combinations.