The Beatles are undoubtedly the most popular band of all-time, so it is no surprise that their first venture into the world of video games - The Beatles: Rock Band - would be a resounding success. Nevertheless, sales of the video game have far exceeded expectations, so much so that Viacom CEO Philippe Dauman is warning that it might not be available for Christmas shoppers.

Speaking with the Wall Street Journal, Dauman said that the "Limited Edition Premium Bundle," which sells for about $250 and comes with a Ringo Starr/Ludwig-branded "Rock Band" drum kit, could sell out by November. Speaking with Wall Street analysts on Wednesday at the Goldman Sachs Communacopia XVIII Conference in New York, he added:

"If any of you out here want to buy some, you better hurry up."

Viacom sold 25 percent of its inventory in the first week that the game was released, which Dauman says was aided by positive reviews that he called "unbelievable."

In addition, he says that the PlayStation3's recent price reduction has also spurred Rock Band sales, and he anticipates another boost in sales in a couple weeks when the price of the Nintento Wii console is expected to be reduced.

The Rock Band franchise is a collaborative effort between Electronic Arts, Viacom's MTV Games and Harmonix Music Systems.