Here's an excerpt from Play.tm's preview of Fallout: New Vegas:
So later in the demo when we betray the loyalty of the New California Republic by activating the Helios One plant's generator to reroute power to the Archimedes II orbital laser, only to rain florescent laser-flavored death upon the NCR troops on the ground, they'll remember it and will potentially never trust you ever again. But then again, it is easy to slip past the facility's idiotic custodian, Fantastic (who has a "theoretical degree in physics"), and once you get to the generator, you're presented with a variety of options that come with a variety of consequences. Still, it's worth remembering that just because there's a gigantic space laser at your fingertips, you don't necessarily have to use it to melt everyone.
Already we've seen a lot of Fallout: New Vegas' opening moments, but Avellone is far from finished, jumping to Primm; another derelict town overrun by Raiders that's distinctive with an old rollercoaster surrounding it and being home to the besieged Bison Steve Casino. Then there's Novac; a city so-called because the entrance is flanked by a broken 'No Vacancy' sign that reads 'No Vac'. Ah! I see what they did there! Upon entering Novac, you immediately see a huge motel sign, which also happens to be positioned by a towering dinosaur-shaped former gift shop called Dinky, which now operates as a perfect sniper nest. It's here that you'll find ex-NCR member Craig Boone, a crack shot sniper who can join you as a partner.
Even later into the extensive hands-off demo, we encounter another partner character, Raul the ghoul, who dwells in a small facility near the central Black Mountain location where an insane, aggressive breed of super mutants returning from previous Fallouts reside. Joining forces with Raul, we take on the band of Nightkin super mutants who have been driven mad by an over exposure to Stealth Boy technology. Using the new grenade machinegun - which spits out grenades at an incredible rate, the Nightkins and their cross-dressing, peroxide-wigged leader, Tabitha, soon fall under a torrential downpour of explosive projectiles, making Raul and the Brotherhood of Steel immensely happy as a result.
These actions also make the opposing breed of New Vegas' super mutants - a more intelligent kind that can talk and articulate - increasingly fond of us more for killing what they call the 'dumb-dumbs'. As one breed of irradiated super mutants naturally hates the other, you can play them off against one another and sit back and watch as they fight, which is something that extends to all of Fallout: New Vegas' opposing factions. You can use the reputation system to your advantage, orchestrating Machiavellian machinations behind the scenes to eradicate your enemies and stay in favor with the communities and factions that matter during your journey.”