I actually just sent my TA a note to book us on one of these in Feb. It wasn't so much that it is a Pixar cruise though, it's just that the dates match up with what I wanted.

I imagine the activities will be similar to the MDAS and SWDAS, so character interactions, special menus, special events that get the audience involved. I have been reading your trip reports and you said your son is 1? I think that will be a perfect age for this cruise.