When the cavs brought in Shaq it was for one reason - to deal w/ Dwight Howard. And, when they played each other, shaq did his job - got howard in foul trouble and rebounded. Beyond that, he really struggled against smaller, quicker centers.
Coming out of the west and not having to worry about Dwight until the finals if at all, I'm not sure why he would be a fit here. I think the smaller centers out here would give him fits.
I like the move for cleveland if they keep lebron. They need a more athletic big than shaq or z. If lebron leaves, I might as well play center for them - they'll be awful.