XCOM: Enemy Within is "Too Big" to be DLC on Consoles

Talking with Joystiq, XCOM: Enemy Within senior producer Garth De Angelis explained the reason they went for a stand-alone release on consoles, rather than releasing it as an expansion as on PC. As it turns out, it was "too big" to patch in:
The reason for issuing the Commander's Edition is because Enemy Within is simply too large a file to patch into the console game as DLC. "For the expansion on the PC, it was fairly straightforward," Garth DeAngelis, senior producer at Firaxis Games, said during a PAX Prime interview. "But when it came to the consoles, it was too big. If we wanted to deliver the same content to the console players, we had to do it this way as a standalone expansion on a disc. We couldn't simply just patch it in."

DeAngelis added that Enemy Within includes so many changes to the base XCOM: Enemy Unknown experience new unit types, upgrades and even skill changes it necessitated an entire re-issue of the game. "These things are tied deeply into Enemy Unknown so we wanted to release [the Commander's Edition] as sort of the ultimate edition, with all the previous DLC on this one disc. It was either deliver it this way or not deliver it at all."

Thanks, Destructoid.