PS2 is king of consoles. That may probably never change as long as Nintendo GameCube and Xbox continue to struggle.
The real battle is between Nintendo and Microsoft. The oldest most-talented, video games developer VERSUS the newest least-talented, video games developer.
In case you may not have noticed, Nintendo builds the success of their consoles based on their 1st-party franchises: Mario, Zelda, Pokemon, Metroid, etc. Nintendo is not known for a good amount of 3rd-party support. Most gamers who have Nintendo systems only keep them for the 1st-party Nintendo-made games.
Microsoft is trying to copy the strategy of Sony, using a heaping support of 3rd-party developers to make games that will appeal to all gamers. This seems to be working for now, though they are still light-years away from the success that Sony has. Sega has supported Xbox since the beginning, though they are now starting to broaden their horizons towards other platforms PS2 and GameCube... Other once-exclusive Xbox developers are also going to other platforms as well, which means bad news for Microsoft.