Update:T-Mobile has added the E315 back to the store, with a new lower price. For the next week you can snag the phone for free. It's not clear why the device was removed prior to the sale.
T-Mobile USA recently removed the Samsung E315 from its phone listing, just two months after launching it. The cause for the removal is still unknown, though it is unlikely a supply problem--T-Mobile.com typically marks phones as "Out of stock" when sales outpace inventory.
This lineup adjustment comes after the carrier removed Sony Ericsson's long standing sales champ, the T610. Rumors have swirled for months that T-Mobile could pick up the newer Sony Ericsson K700, though no hard evidence has been uncovered. Other rumors state that T-Mobile is unhappy with Sony Ericsson and wishes to rid its lineup of the devices. Time will tell.