The Fallout: New Vegas mod has been vigorously worked on for a year. The mod is quite large in size, as it's set to add the ruins of Portland as a location, as well as space, and a new vault. New Vegas is moving from the desert to the icy cold tundra, and is going to be very heavy on a warfare aspect that allows players to immerse themselves into a frontline experience. Frontier will have new monsters, new weapons, and a new storyline, not to forget that 16-kilometer square map mentioned earlier. The mod is almost to completion with the scripting being the only thing that needs the most work. The mod will also allow for you to use your current New Vegas character in Frontier.
You can follow the mod's progression on the official Frontier site.