We've just received a tip from a source with a reliable track record regarding some cut material from Fallout: New Vegas. Given we have very good reasons to believe this is all true, we figured we might as well share it, especially given it includes a few juicy bits.
* We already know that Freeside and the Strip were meant to be single worldspaces rather than broken up in little pieces, and that they were changed to make the game run on consoles and lower end PCs, but apparently a few other areas were affected: originally the Crimson Caravan Company area, North Vegas, Westside, the Aerotech Park and the Fiend territory were all part of the main worldspace rather than separated by a loading screen. After trying to get the game to run on consoles like that and not getting good results, they made each of those areas its separate worldspace.
* When Ulysses was still a companion in the game, he was indeed meant to be recruitable at the location that became Wolfhorn Ranch, as some people have guessed from the fact that the location was called "Ulysess' camp" in some localized versions of the game. This version of Ulysses would actually not be open about his allegiance with the Legion, but rather try to gently steer the character to more pro-Legion views while offering commentary of the various locations and events of the game. Ulysses would only openly admit his pro-Legion beliefs when dealing with a Legion-affiliated PC.
* You might remember that the Fallout wikis used to note that NPCs will cheer at the death of the NCR Drill Sergeant. That doesn't actually happen in the game, and has been removed from Nukapedia's page since then (there's no older version on the Vault, likely because this change predates the split). We can confirm that the idea floated around the dev team at one point, and was possibly even implemented just to be scrapped later on.
* The Black Mountain location was meant to play a larger role in the NCR/Legion conflict at one point, with factions interested in controlling it due to its satellite system (the NCR to expand their broadcast range and the Legion to use as a jamming system). Digging through the files of the game one can still find some references to a quest that involved blowing up the satellite dishes that was tied to that older design of the area.
* The Securitron Marylin, a flirtier counterpart to Jane at the service of Mr. House, was cut due to unconditionalized/missing dialogue that couldn't be re-recorded at that point in development. Some NPCs had similar problems which is why you see so many "..." goodbye lines in the final title.
* There are references to an "Underpass" area in the game. This cut area was never really meant to be particularly relevant and was based around Brahmin farmers. You could find it on the north end of the map, north of New Vegas Clinic.
* A lot of work had to be scrapped after the post-Hoover Dam gameplay was cut, including the option to help the Omertas take over the Strip as a consequence of a successful execution of Operation Racket.
* At one point during development you'd be able to actually work with the Fiends, which explains the cut dialogue for the Three-Card Bounty quest. You could allow the Fiends to break into Camp McCarren (referenced in some of the ending slides) and you'd be able to witness the consequences of that action in post-Hoover Dam gameplay.
* The dead Powder Ganger in Quarry Junction, Hawkins, was actually meant to be up one of the rock processing machines rather than the location he is in in the final game, alive. He had an attached quest to save him from the deathclaw infested location (the reward being simply some money) and in terms of dialogue he'd feign ignorance about the activities of the Powder Ganger. Speaking with Chomps Lewis would let you unlock a dialogue option to call him out on that. This cut was likely done because as development went on the area became more obviously geared for high-level players, so such a minor quest would have been pretty much inconsequential.
* In the original design Freeside was meant to lose power between 11pm till dawn or so, making the choice to route power to the location more relevant, as it'd mean that the Followers would be able to continue operating during the night too.
* At one point the game included a trader named Felicia who would give you items such as stealth boys, mini nukes and energy cells for Sunset Sarsaparilla bottle star caps.