Sony has announced that PlayStation 3's online function won't feature a central service similar to Xbox Live. Instead it will have an 'open architecture' that allows games publishers to decide how they want gamers to get online with their games.
With Xbox Live, publishers have to work with Microsoft, which is something that prevented EA's Xbox games going online until 2004. It seems a similar service to Xbox Live does not appeal to Sony as its approach focuses on giving flexibility and freedom to individual publishers.
However, it hasn't worked especially well for PlayStation 2's online performance, which is well behind Xbox Live in popularity.