For those of you who purchased new Apple devices with the iOS 5 software or have recently upgraded your iPod Touches, iPhones, iPads to iOS 5, please read the following:
Regarding the issue of WMA files not showing up on an Apple device following the update to iOS 5, users can now update OverDrive Media Console for Windowshttp://www.facebook.com/OverDriveForLibraries
(http://www.overdrive.com/software/omc) to resolve the issue. Once you have transferred a WMA Audiobook to your device, a playlist will be created for the Audiobook. Please note that WMA Audiobooks will no longer be listed in 'Audiobooks' on your iOS5 device. This solution will work in the absence of a patch from Apple that would allow WMA titles to be named properly and stored under Audiobooks on a device using iOS5.
I'm not completely sure this will work, but if you view the last few slides in the presentation for Mac users, there are screenshots that show how to make an audiobook show up as, well, an audiobook! If this works for you, let us all know.