Bethesda Softworks has announced that Old World Blues, the third Fallout: New Vegas add-on, which was originally scheduled for a June release, will come out on PC, PlayStation 3, and Xbox 360 on Tuesday, July 19th. The final DLC, Lonesome Road, was to be released in July, and will likely be delayed even further as well.
In Old World Blues you will discover how some of the Mojave’s mutated monsters came to be when you unwittingly become a lab rat in a science experiment gone awry. You will need to scour the pre-War research centers of the Big Empty in search of technology to turn the tables on your kidnappers or join forces with them against an even greater threat.
Prior to release, Bethesda will also release a new patch for New Vegas, which will add not only support for Old World Blues, but also performance and stability improvements.
They have also released some new screenshots from the upcoming add-on:
Source: Bethesda Blog