As of this week, GameStop has begun accepting iDevice trade-ins at its retail outlets for in-store credit. 9to5Mac is reporting that GameStop will soon offer Apple’s entire lineup of iDevices for sale, and it’s speculated that GameStop is accepting new and used trade-ins first to make room for new products this Fall, like the iPhone 5.

Resellers are gearing up for a mass influx in used iPhone trade-ins, with Apple’s next smartphone slated to make its debut before the end of next month.

From GameStop’s trade-in Terms and Conditions:

“Trades must be in full working condition to receive full value. Trades with case damage or unsightly scratches, personalization or engravings will not be accepted. All trades are subject to manager approval. GameStop reserves the right to cease taking trades of iPod, iPhone or iPad without notice. By trading your iPod, iPhone or iPad you release GameStop from any claim relating to the product (including but not limited to loss of the iPod, iPhone or iPad or its contents) and any music, pictures or other data stored on it. You also release GameStop from any claim for loss or unauthorized access, use or disclosure of any personal or private data or information stored on the iPod, iPhone or iPad. iPod, iPhone, iPad (including images of the iPod, iPhone or iPad), and Apple are all registered trademarks of, and owned by, Apple Inc.”

Gadget resellers, like Gazelle, expect a huge amount of used iPhone sales in the coming weeks, and GameStop’s new trade-in program will surely garner much attention from consumers this holiday season.

Apple is gearing up for what will undoubtedly be a huge holiday quarter, and the iPhone 5 is rumored to already be in production overseas. Today, Deutsche Telekom started offering pre-orders for the unreleased device, and it’s expected that Apple will hold its next media event this month.