A new Xbox 360 SKU is starting to appear on store shelves – but Microsoft hasn’t officially told anyone about it yet. Gamers knowing the differences between each of the various Xbox 360 models have snapped pictures from retail showing a new Xbox 360 Arcade package selling at $279.99.

At $279.99, the Xbox 360 Arcade hits at the exact same price as the Xbox 360 Core system – and will likely become the new entry-level SKU for Microsoft’s console. The new Xbox 360 Arcade package will improve upon the Core in several ways. While there will not be a standard hard disk drive, the Arcade system will ship with a 256MB memory unit – an accessory that previous Core buyers had to purchase separately. Another upgrade that the Arcade unit enjoys over the Core is the move to a wireless controller complete with a set of free Energizer AA batteries. Previously, only the Xbox 360 Premium and Xbox 360 Elite came with wireless controllers.

Pictures of an unboxing process hosted at Engadget reveal that the Xbox 360 Arcade system features an HDMI port, even though only a standard-definition composite cable is bundled. This means that the Xbox 360 Arcade ships with either a Zephyr motherboard – the first Xbox 360 revision to include HDMI – or a Falcon motherboard, which added further improvements while shifting the CPU from a 90nm process to 65nm.

The Xbox 360 Arcade system gets its name from the Xbox Live Arcade compilation disc included with the system. Games a part of the pack-in are: Boom Boom Rocket, Feeding Frenzy, Luxor 2, Pac-Man Championship Edition and Uno.

Curiously, Microsoft announced just a week ago new holiday bundles for the Xbox 360 Premium and Xbox 360 Elite, which added Forza Motorsport 2 and Marvel: Ultimate Alliance games for free, but did not mention a new entry-level model called the Xbox 360 Arcade. The new Xbox 360 Arcade was already listed at retailers Amazon.com and Toys “R” Us, making Microsoft’s silence on the new product rather puzzling. Information on Microsoft’s holiday line-up first came at the Leipzig Games Convention during August.