The Boy Genius Report has published a rundown of the new features in iPhone OS 4.0 beta 3. File sharing through iTunes, media player controls in the app switching tray, a quicker way to close apps, and an orientation lock are all mentioned. There may be more features in beta 3 but these are the most important ones.

I’m happy to finally see an orientation lock, this is something I’ve been hoping for since the iPhone first came out. And, I’m also happy to see that Apple has brought back media player controls for the double click home button shortcut. I rely heavily on this feature and use it more often than you might think, when I was running beta 1 this was one of those missing features that drove me absolutely crazy.

Arnold Kim, of MacRumors, is also reporting some interesting findings in beta 3. He reports that OS 4.0 gives developers full access to video capture which will make for some much more functional video recording and editing applications. But, the new APIs don’t just let you capture video at 640×480 but also reveal the ability to capture video at higher resolutions, such as 1280×720.

The camera in the next iPhone was rumored to be of the 5 megapixel variety. But, this news of higher resolution video capture adds credence to the rumored “iPhone HD” name. And, if these camera rumors are true, the iPhone is giving even better reason to carry it as your one and only device.