If the games are $50, then Nintendo will be handing a critical advantage to Sony and the PSP.
Everyone knows that GBA game profits are slim. Sony has said that they aren't going to be able to sell the hardware at a loss, if they want to keep the game prices in line with expected standards.
If DS games are more expensive, then the PSP's games will obviously be less expensive, which adds up to savings for the consumer, leading them to do otherwise crazy things like drop $450 on a PSP. Or, the PSP games might raise in price (and profits) too, which would give Sony exactly what they need to come down from that unacceptably bad price point.
At any rate, at least it's good to see some source pointing out that the DS ain't gonna be $450, just for all those people who you think should know better, but don't. (Just earlier today my older brother came over, asking if I had heard the amazing news that Sony had unveiled their PSP at E3...)