Yes, you're right. I was thinking of PS3/360 development costs.
Iwata mentions in the interview NWR references, that the 3D effect isn't what will drive the dev costs up, (near Wii dev costs which are $10million and less) its the base graphics, which are so high above the DS. He also says that only a developer taking maximum advantage of the 3DS's graphical capabilities will have higher costs. He also says that not every developer would need to make a significant investment for their games, but those who put in the same amount of effort as a console game will please their customers...
Would it really be too much for Nintendo to have a minimum graphical standard so that we don't get games with DS graphics in 3D?