Windows/Mac: iTunes 9.2 has rolled out, preparing computers for the coming of the new iOS 4 upgrade and the iPhone 4. But there's also PDF support rolled into iBooks for iPhones and iPod touch models, and faster device syncing.
The faster device syncing is only for devices that will run the (upcoming) iOS 4 operating system, but since it's a free upgrade for nearly every device, that's a pretty universal upgrade. Along with the future iPhone support, iTunes 9.2 also displays album art faster while flipping through your library, and allows for the organising of apps into folders, another iOS 4 feature that's a welcome upgrade for those with cluttered home screens.
iTunes 9.2 is a free download for Windows and Mac devices. It weighed in at 121MB on a Mac, and requires 200 MB free on Mac and Windows.