Even if Orci and Kurtzman don't write TF3 it doesn't mean that Bay will. They'll probably get new writers to replace them; and I don't think any new writer(s) should be judged till we see the next movie. Then of course, it still boils down to how much Bay will tamper with the script. Directors and actors deviating from the script isn't necessarily a bad thing... but history has shown that with Bay it's often not a good thing and it's probably best if he didn't. :/