N-Sider member Juno Reactor considers the reason why the Nintendo DS brand has replaced Game Boy...
The original Sony PlayStation 1 continued to outsell the PS2 several generations into the PS2's lifespan, at which point PS1 sales petered out in the midst of public perception and fewer new games. I think it's only a matter of time before the Nintendo DS does the same to the Game Boy Advance. I'm already starting to see children, the main audience for the GBA, playing the DS in public more often. I'm a server part-time at a restaurant, and it's not uncommon to see the little ones petting Nintendogs or Pictochatting while they wait for their food. Imagine how ubiquitous the DS will become among that demographic once Pokemon Diamond and Pearl hit stateside, coupled with additional price drops, bundle deals, and word of mouth.
The simple fact of the matter is that the DS is a Game Boy, only with new input features that make it better. A more powerful Game Boy has no defining features to justify its existence alongside such an all-in-one system -- especially one as sleek, compact, and portable as the DS Lite. Besides, while the Game Boy brand has been successful, its appeal has sharply defined boundaries, and the name has negative, childish connotations among older people. Nintendo is striving to change their image with completely new brand names, to the point where Nintendo even omitted its own name from Wii.
The way I see it is that the Game Boy was the product of the tail-end of the Hiroshi Yamauchi era, a time which was a dark period for Nintendo. The DS, on the other hand, is the brainchild of the Iwata-age, a time where people are predicting Nintendo's return to glory. The DS is the way forward, and the Game Boy is a relic of a bygone time. That's what I think Nintendo's thinking.
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