GBA and Gamecube Left to their Own devices

As expected now the Wii has been released and the DS is so strong, an article on buisness week discusses the future for the GBA and Gamecube:

The overarching message for Nintendo appears to be a relatively simple one this holiday season, as simple as they would claim the Wii Remote is to use—appealing to gamers, be they young, old, hardcore, non-traditional or lapsed. And while the $200 million for advertising the Wii turned out to be an erroneous number (that's apparently Nintendo's annual marketing budget), Nintendo is obviously trying hard to get the word out.

But that leaves one final question: what about Nintendo's older systems (GBA, GCN)? The GBA had a very solid November, with over 600k hardware units sold and if there was any time for a last push with the GCN, now would be it. Dolecki offered, "Our focus right now is on Wii and DS, but we have a huge installed base of Game Boy fans. Third-party publishers have tapped into that audience, and we have a library of nearly 950 games for GBA," she said, adding, "Nintendo GameCube owners can also experience The Legend of Zelda: Twilight Princess. "

The fact of the GBA still selling really astounds me especially with the DS being able to play GBA games. But surely the GC is now in the "overlap" stage, where the end of one consoles life and the life of it's successor intertwine.