Yeh I read the article a while back also at xsi base.
From what I read and heard, the character animators at ILM have so much invested in Softimage 3d (soft, the old version prior to xsi) in R&D and user experience that they thought it wise to stay with Softimage and move onto xsi.
ILM has also formed some alliance with Mental Images creaters of U guessed it 'Mental Ray'. This is I believe another reason ILM chose xsi as its main character package.
As for workflow, well..............
Not to start a software war or anything.
Have used (worked through tuts and played with somewhat) xsi for about 6 months now.
xsi has no set driven key command. The closest thing it has is link with and link multiple. Which is an absolute pain to setup.
Animation playback is not in real time (for similar scene in Maya = Real time).
xsi has some great features but on the whole feels like the poor cousin of Maya.
Having said all this xsi has some really cool features that would be very welcome in Maya such as:
coloured joint skin weights to show the weight mix on all points.
weight curves on the actual 'clip' in their version of the non linear animation mixer. It is really helpful to see the actual weight 'f' curve displayed on a clip so you can visually see its contribution to the mix of clips.
Very, very fast SubD's with excellent proportional modelling tools.
xsi's verion of IPR supports GI, FG, Caustics, raytracing, particles, volume effects, motion blur, DOF, blah, blah, blah. Iv'e also had it running (their version of IPR) for 2 days straight at production quality doing HDRI work and not a single crash.
Things for AW to think about.
But, I still love Maya!!!!!!!!!!!!!!
Mayan elder......only in years.....