I think DS is going to have a very long, very healthy run. The price has only been dropped once, temporarily... So right now it's closing in on 1/2 of PS2's LTD WW with no real price drop!!!
DS will hit about 20 million in America by year end, and it could go on to sell another 10 million next year. Even if Nintendo cuts the DS' price next year, they aren't going to launch a successor only a year after their first price cut! So DS' successor is coming in 2010 at the earliest. And DS will keep selling for at least a year after it's successor comes out.
So I have little doubt that DS can pass GBA.
The next question is PS2, which will hit 50 million in shipments to America... DS may need more mega-software like Nintendogs/Brain Age/Pokemon/NSMB to make a run at 55 million or more. But I think that's entirely possible.
"[Our former customers] are unable to find software which they WANT to play."
"The way to solve this problem lies in how to communicate what kind of games [they CAN play]."
Satoru Iwata, Nintendo President. Only slightly paraphrased.
