As expected, a massive upgrade to the iPod touch was announced earlier today at Apple’s special event. Although the most outwardly impressive revisions come by way of front and rear facing cameras and the retina display, perhaps more significant was the announcement that the device would house the same chip capably powering the iPhone 4 and the iPad — the Apple A4.

The A4 mobile ARM processor is of particular importance when considering Apple’s mobile future. With today’s revelations that Apple has sold 275 million iPods and that 1.5 billion games and entertainment titles have been downloaded on the iPod touch alone, it’s not a stretch to see why Game Center was a cornerstone of the presentation.

While Nintendo and Sony have both been busy manufacturing dedicated mobile gaming platforms, Apple has seized control of over 50% of the worldwide mobile gaming market with multi-function devices like the iPod touch. Although Apple has the market share, the more dedicated game design houses have, for the most part, stayed, in the Nintendo and Sony camps. For Apple to maintain market dominance, it’s going to have to start catering to more serious gamers, and that’s exactly what Game Center is all about.

A cornerstone of the presentation was codename Project Sword. Developed by Chair Entertainment, makers of the Xbox Live hit Shadow Complex, Project Sword will utilize the Unreal 3 engine, making it undoubtedly CPU-intensive. Despite all of that, let’s not sell its surface features short.

The A4 might be the linchpin of the device, but Apple has historically pushed more units based on looks than outright performance. The addition of a front facing camera to the iPod touch will put FaceTime in the hands of millions of new users, which could be enough to tip the scales toward actual usefulness.