Fallout 3

[NokkonWud]

I've still not found the comment regarding new DLC after Broken Steel that I read before, but this is something I've just read:

Originally Posted by Gamespot

Fallout 3 ended up being one of last year's best role-playing games, and creator Bethesda Softworks intends to keep people playing it by releasing new downloadable adventures. The next downloadable content (DLC) will come in the form of Broken Steel, a new adventure that focuses on the mysterious wasteland knighthood known as the Brotherhood of Steel.

In that context it seems pretty clear that there will be another one after Broken Steel.