MSN Entertainment and Video Services general manager Rob Bennett sent out an e-mail this afternoon to customers, advising them to make any and all authorizations or deauthorizations before August 31. "As of August 31, 2008, we will no longer be able to support the retrieval of license keys for the songs you purchased from MSN Music or the authorization of additional computers," reads the e-mail seen by Ars. "You will need to obtain a license key for each of your songs downloaded from MSN Music on any new computer, and you must do so before August 31, 2008. If you attempt to transfer your songs to additional computers after August 31, 2008, those songs will not successfully play."Link
This doesn't just apply to the five different computers that PlaysForSure allows users to authorize, it also applies to operating systems on the same machine (users need to reauthorize a machine after they upgrade from Windows XP to Windows Vista, for example). Once September rolls around, users are committed to whatever five machines they may have authorized–along with whatever OS they are running.