Imagine if your PS4, Xbox 720, Wii U or PC game all shared the same exact server for online gaming. You could play with people that own any system with the game game and it'd revolutionize the online gaming industry. Bungie's upcoming "Destiny" game will be the first game to introduce the "shared world" idea by using 1 enormous server. If "Destiny" is a major success, could all developers attempt to try the same idea with their games?
One of the slight issues with sharing the same servers is specific usernames. Imagine if the same 2 peeople had "cooldude69" on 2 separate systems. One way to challenge this is to add a tag for each username which depicts which console they're using. For example, if "cooldude69" was using a PS4, his username would be "cooldude69(PS4)" and the other person using the name would be "cooldude69(XB)" if they were using an Xbox 720.
Using the same server for different consoles would truly introduce the 8th generation of online gaming. Of course, to help pay for these massive servers, the game itself could require a small yearly payment. If the online service already costs money like Xbox live, the yearly payment for the game may be lower or non-existent. This could happen for games like "Destiny" which is expected to have a 10-year life cycle. It'll make more sense for developers to cut any additional costs and just feature an enormous shop to let gamers buy new items.
Once games for the PS4, Wii U, Xbox 720 and PC all share the same server, gaming would truly get serious. If someone were to play a future 'Call of Duty' title, they would have the same experience with any platform. You wouldn't have different ranks on different systems unless you decided to and it'd be a much more unified experience. No matter what developers decide to do in the next few years, it's expected to blow the minds of gamers everywhere.