The Elder Scrolls 5: Skyrim have been shipped out to retailers since launch, which represents $650 million in potential sales so far. Keep in mind that those copies are shipped, not sold. Sales for the RPG are doing well so far, and odds are quite a few more of those shipped copies will find their way into homes and stockings this holiday.
Zenimax also reports that Skyrim has outsold all other PC games by a factor of three to one in the month since its debut, and currently holds the title for the fastest-selling game in Steam's history. Star Wars: The Old Republic is set to officially arrive next week, so it's hard to see Skyrim holding up that ratio on PC for much longer.
In summary: infinity times ten million equals a hell of a lot of dragons.