There's an unused, incomplete script in F:NV called vChipHistory. It tracks the player giving the Platinum Chip to one of four factions, Mr. House, Legion, NCR or the Followers of the Apocalypse. It then tracks the player stealing it back and giving it to one of the other factions. Was F:NV's main quest even more ambitious early in development?
The main plot did revolve around the platinum chip floating around for a while. Shortly after this version of the critical path was stubbed in, I talked to John Gonzalez (our creative lead) and asked him to change the focus of the second half of the critical path. I was concerned that it was too “foozley” and didn’t focus enough on the factions and their interests in the war. He redesigned the second half of the critical path to faction interactions and motivations.