I assume by switching brains/souls you don't mean literally switching the organs, since part of your behavior comes from your brain makeup and chemistry, not just from your experiences...etc
If that's the case and you just switched "souls", then I think everything would be exactly the same as it is now... I guess I don't believe in free will after all.
I remember a thread that talked about something along these lines, about how your actions depend on you past experiences, and those depend on other peoples actions/experiences...etc all the way back to the beginning of time. I agree with this view, that the universe is deterministic.







