And as Nem pointed out, they had been using softimage3d and I believe that they announced they were switching to xsi from softimage3d, not that they were throwing out all the other software they use.

If you think about this though.. ILM hasn't won an Oscar for visual effects in two years... Winners were ESC(or was it Manex) for Matrix and Weta for LotR whose main package is Maya But like shoaib said, it's the artist, not the software