- There is an optional hardcore mode, the character needs to drink water, ammo has weight, healing isn't instant etc. Normal mode is more similar to Fallout 3 gameplay.

- The storyline is focused on the New California Republic vs. Caesar's Legion vs. New Vegas residents.

- You are not a vault dweller but are given a Pip-Boy by someone who is one.

- There is a screenshot of a vault suit as well.

- There is an assault rifle looking like the M4, as well as a new big gun with a backpack, held like a minigun.

- There are special moves for melee weapons in VATS - specifically a move for a golf club called "Fore" which seems to be a groin shot.

- The Hoover Dam is in the game and is supplying electricity to the city.

- There is a quest to rescue a ghoul from some super mutants. The ghoul can then become your companion

- The Geckos are back.

- There are both dumb and intelligent super mutants, including the elite Nightkin.

- Some super mutants look similar to the ones in Fallout 3, while others are new. There is e.g. a female super mutant with a 1950s hairstyle who apparently is one of their leaders.

- Screenshots include a guy with a beard and straw hat, a ghoul an NCR Ranger

- The only picture of New Vegas itself is concept art and not a screenshot

- Some location screenshots include a huge model dinosaur advertising a hotel, some satellite dishes, an array of solar panels

- A character generation shot showing a "vigour machine" instead of the skill book

- NCR base is the McCarran Airport, Caesar's Legion is based in the Vegas Strip, while super mutants are based in a place called Black Mountain. There is also a town called Fremont and another called Primm. A topless reuve is mentioned as being in the latter.

- NCR Ranger armor is similar to a brown combat armor with sleeves, there are concept arts of a Ranger

- Skils have a bigger effect on conversation choices. E.g. someone with a high Explosives skill may be able to have a coversation about explosives where appropriate.

- There is a Reputation system in adition to Karma.

The list is being updated as new details are being mentioned in the forum.

Obsidian's Fallout: New Vegas introduces a Hardcore mode that challenges players with dehydration, ammo weight, non-instantaneous healing and tougher enemies, according to a new preview in PC Gamer (reported by Duck and Cover).

Super Mutants will also be more intelligent and varied, and there's an elite Nightkin enemy and a female mutant with a 1950s-style haircut who may be important.

Fallout: New Vegas is set in the Mojave desert, and apparently the area of Vegas wasn't hit hard in the apocalypse so many buildings remain intact. The storyline follows a conflict between the California Republic, Caesar's Legion and New Vegas residents.

You are not a Vault Dweller but a courier, dug up by a robot and nursed back to life by a doctor. You'll take vigour tests to set-up your abilities and then be given a Pip-Boy by the once-Vault dwelling doctor.

New Vegas also has a Reputation system on top of the Karma score, and these will tracked by each settlement independently.

VATS will return, but this time with added melee moves such as swinging golf clubs into people's groins. Skills will play a larger part in conversations, unlocking new paths should your relevant ability be high enough.

You'll still be able to try the alternative conversation path if your skill is lower than recommended, apparently, but your chances of succeeding are slim. Luckily, Fallout: New Vegas will not penalise for this, but rather response wittily should you try. Barter well and you will not only lower prices but also increase rewards.

Players will be able to recruit followers and issue them basic "follow", "stay" or "attack" commands. One example of a companion is a ghoul that players will rescue from a pack of Super Mutants.

There's a new assault rifle that looks similar to an M4, as well as a big gun that uses a backpack of fuel or ammo.

Fallout: New Vegas will be released this autumn on PC, PS3 and Xbox 360. Sequel-specialist Obsidian is at the helm, following work on Neverwinter Nights 2 and Knights of the Old Republic 2 for BioWare.

Character creation: G.O.A.T. is replaced with a psychoanalysis test.

Some NPC companions will have their own quests too, not only Raul.
Radar: A new yellow bar for companions is added by Obsidian.

Weapons: picture of a hunting rifle included. Available modifications are scope, larger magazine and a 3rd one for faster load between shots.
Weapons: picture of a normal and a unique 9mm Pistol. Shown mods: scope and magazine enlargement. One gun shown with both scope and enlarged magazine.
Weapons: The unique pistol has a unique skin, engravings and a picture of Virgin Mary on the grip. This could mean that every unique weapon has its own skin. "These rare guns not only look UNIQUE, but have unique properties."
Weapons: Concept art of a guy in the trenchoat from the teaser wielding a Fallout 3-style minigun (It's a little bit smaller though)
Hint that weapon modifications can be found in the wastes. (May be speculation)

you easily gain access to ............. by having a good reputation with NCR and BOS