wiiwareToday, at the Game Developers Conference in San Francisco, Nintendo announced that a new online service for its Wii video game console called WiiWare will be available on May 12. This service will allow independent developers to create their own games for the popular system that any user can download directly to the console.

Such a service could be a real boon for the Nintendo Wii similar to how Facebook exploded with popularity when it launched its platform for independent developers to work with. Not that Nintendo needs more popularity — since the console launched in late 2006 it has massively outsold both of its chief competitors, Sony’s Playstation 3 and Microsoft’s Xbox 360. In fact, the Wii is selling so well that Nintendo is still having trouble meeting demand nearly a year and a half after the console’s launch.

Nintendo plans to allow for variable pricing on games sold over WiiWare and will utilize their Wii Points purchasing system currently in place on the online portion of the Wii.

Also of note is that games will not have to receive approval from Nintendo to be listed on the service according to The Wall Street Journal. Games will simply have to be rated by an industry rating system that establishes the age-appropriateness of the game. The openness of the system should allow for some true innovation in games when combined with the Wii’s motion-sensing control system.

Microsoft currently sells games over its Xbox Live system, but most are made by larger gaming companies or are versions of successful arcade titles. Sony has also made downloadable games available for the Playstation 3, but many of those are created by Sony themselves.

[update]: Microsoft has just announced that they too will allow for independent game development on their Xbox Live system. They hope this will double their Xbox 360 game library by the end of the year according to USA Today.

We’ve covered the Microsoft announcement separately, here.

Nintendo also made news at the GDC by announcing the American launch date for its new Wii Fit game. On May 19th, consumers will be able to purchase the game that features a new peripheral known as the Wii Balance Board to allow for a new kind of experience in playing. Wii Fit will focus on fun games to get players’ bodies active much as their successful Brain Age software worked out a player’s mind.