Towards a 4 GB iPhone 3G?

When the iPhone was initially launched, Apple offered 2 models differing only by their storage capacity 4 GB or 8 GB. Most customers purchased the high-end model, and Apple rapidly stopped the production of the 4 GB model while dropping its price.
According to Boygeniusreport, Apple might offer a new iPhone 3G, featuring only 4 GB of storage space, in order to further decrease the price of this model and offer an entry-level model to boost sales on the US market. Such model would then be sold by Wal Mart for 99 USD including a subscription plan. Orange in France is currently offering the iPhone 8 GB for 99 Euro to all new customers.
The idea is not so much surprising, as the main goal might well be the make iPhone owners purchasing from the AppStore than loading their iPhone with music and video, not necessarily purchased from the iTunes Store. Indeed, one should remember than a survey conducted by Apple indicated that in average only 3 albums/iPod were acquired from the iTunes Store. With such a lower storage capacity, the entry-level iPhone might further expend the number of iPhone owners, and consequently the number of potential customers for the AppStore. However, what about the exclusive deal with AT&T?