This passage, right here, is the key to the article:
"As for Nintendo's hit holiday launch of the Wii, Pachter appears unconvinced of the system's long-term prospects. "We believe that the Wii will outsell its competitors by a large margin for at least two years, but have difficulty predicting whether Wii demand will remain strong or will fade thereafter,"
Basically, he's saying that the Wii will dominate for 2+ years, and after that, he really has no idea what's going to happen. He ultimately gives the edge to the PS3 based far-in-the-future price drops, but his suggestions are vague at best.