Illinois is one of several states participating in a consortia "Unabridged" at http://unabridged.lib.overdrive.com with Overdrive audio books in Windows Media. We see that this may be a problem because they will not play on IPODs, the most popular MP3 player at this time. However, many of our readers are older and may not have purchased an MP3 player yet; there are over 500 devices that will work with Windows Media Audio. OverDrive is working on a children's collection but it is not available yet to my knowledge. These just came out in November 2004.
netLibrary/Recorded Books introduced their digital audiobook service in February 2005 - not even a full three months ago. Theirs are in Windows Media audio format also.
These two new services in addition to new audio books from Tumble, are offered by vendors who are constantly seeking feedback from libraries and users about this service. Several of these vendors have even changed pricing plans to better meet library needs and to make it more affordable for small libraries to offer these books.
Audible.com offers audiobooks that will play on an IPOD, but they do not have a library management model, which makes it difficult and labor-intensive for libraries to provide this content.
Soon, these services will also be offering downloadable music, and I think this is where it may hit the hardest with younger users. If, and I know a number of librarians feel that Windows Media Audio is a problem that needs to be addressed sooner than later, they should contact OverDrive, and OCLC/netLibrary and let them know that this is a problem and may affect their sales.