.... will Pixar be able to use film names that were done with Disney as part of their marketing new films ? For example, can they say "From the people that brought you Toy Story, Pixar is proud to announce the release of (fill in the blank)".
I would imagine they can, as those films were jointly produced. Whether the two companies are partners or not, you can't change the past. It'd be a pretty strict seperation agreement if Pixar isn't allowed to claim any past film as their own!