First, read this.
I love the DS. I love it's potential. It's enigmatic uniqueness and potential are some of the reasons I love the thing. But it's not a GB.
Now that the DS is here, it should be no doubt in anyone's mind that GBA sales will fall. Sure, it sold well during the holiday season, but you have to realize that it is going to be the last time the GBA sails well.
When the next GB comes out, DS sails will fall. And since GB is not a DS, it won't be backwards compatible with the DS. So that means goodbye DS, goodbye potential. We'll just go back to playing games the "normal" way again.
I don't care if GBE has GameCube graphics, I don't want the DS to crumble. And I say that the next protable Nintendo makes should be a GB DS, possibly with GCN graphics, and a much better design.
Nintendo could create 2 development kits for developers: 1 kit allows developers to utilize all the functions of the hendheld, whereas the other allows them to only use 1 screen without all the features.