They don't really need to do anything, it is already entrenched. The reason that Live is still successful is because people want to play with their friends, and if their friends have Live, they are not going to change to PSN
Ultimately, they don't need to do anything, they can't do anything that will really make it that much better than PSN, but it is worth it to play with your friends, and having games like L4D2 and other more co-op centric games (Xbox exclusives tend to be more co-op friendly it seems) will also reinforce this







