Today Apple announced the release of the iOS 4.1 Beta for members of their developer program. The new release includes a new API which allows apps to access contact thumbnail images, along with media playback improvements.
Non-developers will have to wait for the official release, but developers can download the iOS 4.1 Beta 3 which works with the iPhone 4, iPhone 3GS, iPhone 3G and iPod Touch (3rd and 4th gen).
Release notes indicate that the Game Center will no longer be supported on iPhone 3G and 2nd gen iPod Touch. Flash and camera buttons will reposition themselves while in landscape mode, and other small issues have been improves. With continued updates, iOS is maturing into a full featured mobile OS that is attracting the attention of developers worldwide.