Virtual Lithics

Skyrim has mods.

This has the potential to become an interesting problem for the game industry. On the one hand, Bethesda is one of the companies that strongly supports the modding community, releasing the Creation Kit for anyone to try their hand at adding new content, changes in focus, or basic bug fixes to the worlds of Skyrim and the Fallout series. This, when it works well, gives games some of the advantage of Open Source. There are some very skilled people out there who don't happen to be working for Bethesda (or who don't have any deadlines other than self-imposed ones) and are able to do things the original creators did not or could not.

On the flip side, official DLC can look bad by comparison. I have to say that Bethesda shot themselves in the foot a bit with Skyrim, at least. The two big DLC's, Dawnguard and Dragonborn, got decent reviews and are considered more-or-less worth the price. However, Hearthfire is considered by most reviewers to be a waste of money, hence a waste of employee hours by Bethesda (unless they got a lot of sucker sales).