Attention, Wal-Mart Shoppers: iPhone 3GS Clearance Sale in Aisle Nine

With two weeks to go before Apple’s annual Worldwide Developers Conference and the presumed debut of the company’s next-generation iPhone, Wal-Mart is dropping the price of the entry-level iPhone 3GS by more than half.

This morning, the retailer cut the price of iPhone 3GS devices with 16 gigabytes of memory from $197 to $97 with a two-year service contract. Wal-Mart claims the reduction is simply part of its “ongoing aggressive savings announcements.” But coming as it does amid speculation about the launch of a new iPhone (and rumors of the discontinuation of the 8GB iPhone 3G), it is being interpreted as a move to clear out inventory before that device arrives at market.

Meanwhile, Apple (AAPL) and AT&T (T) continue to sell the 16GB iPhone 3GS at its original price, though I can’t imagine that this will continue much longer. When Apple introduced the iPhone 3GS in June 2009, AT&T slashed the price of the entry-level 8GB iPhone 3G to $99.

The company is expected to do the same thing this year with the low-end 3GS. And, as it did last year, that price cut will likely spur adoption of the device among the lower tiers of AT&T’s customer base. As BTIG Research analyst Walter Piecyk observed in a note to clients this morning:

We estimate that last years price cut of the iPhone 3G to $99 stimulated more than 3 million phone sales to existing AT&T customers that helped the company further penetrate the family plan with higher ARPU, lower churn customers. We believe the impact could be even larger this year for AT&T given its the broad market acceptance of the iPhone, the halo impact of the iPad and the installed base of iPhones that will need to be upgraded to a 3GS phone in order to benefit from Apple’s latest upgrade to its iPhone OS 4.0.