Nintendo Gal has noticed that Nintendo is no longer selling component cables for the Nintendo GameCube. The cables were previously frequently on back order, leaving those looking for the cable set to find other options such as used and third-party cables.
GameCubes sold since May 2004 have not actually featured a port compatible with the cable set, anyway. At that time, Nintendo determined that less than 1% of GameCube owners were making use of the component video output port, and dropped it entirely, renumbering the system to DOL-101 from its previous incarnation as DOL-001.
Nintendo has not yet said whether GameCube successor Revolution will feature component output, but photos of the system seem to indicate that its A/V port is entirely different than the GameCube's standard A/V port, which has remained the same since its introduction with the Super Nintendo Entertainment System. It's possible that Nintendo may be offering an all-in-one composite/component video solution with the new system, especially considering the increasing prevalence of sets with component options.