While we don't know what new features Amazon will offer, the company will likely eliminate the need for users to upload every one of their songs individually to the cloud. Because Apple obtained licenses before launching its cloud service last year, it was allowed to scan a user's hard drive to identify the music there. The company could then match and stream songs to the user from copies stored in the iTunes' library, eliminating the tedious uploading.
The company is said to have reached agreements with Universal, EMI, and Sony, and is in late stage negotiations with Warner.
Yesterday, Amazon finally launched their Cloud Player app for iOS.