The odds that Apple’s iTunes will become the #1 music retailer in the U.S. in 2008 are 5:12, according to online casino Bodog. The odds that it won’t are 18:11, meaning that the site is laying heavier odds on iTunes overtaking Wal-mart to become the biggest music retailer in the U.S.

J. Freedom du Lac noted the proposition bet at his Washington Post blog Friday, with the wager itself being made available after NPD group announced earlier this week that iTunes became the #2 music retailer in 2007.

As noted by Mr. Freedom du Lac, the rules for the prop bet are as follows: "If it is not officially announced by December 31, 2008, that iTunes has surpassed Wal-mart as the No. 1 U.S. music retailer," according to the wagering board on Bodog’s Web site, "all ’No’ wagers will be graded the winner. Max. $50."

It should be noted that it took until February of 2008 for the NPD Group to announce its results for calendar 2007, whereas the wager itself stipulates that the announcement be made by December 31, 2008.

In a world where most anything can be wagered on through online and brick and mortar casinos, it may not come as a surprise to see Apple be the subject of a prop bet. It is, however, interesting to see the odds makers betting so heavily in favor of Apple’s success.

We should also note that the online casinos exist in a grey world, at best, in the U.S., where federal law has made it difficult to move money to and from the casinos. Accordingly, don’t confuse this article with an endorsement of the prop bet.