First, I should mention that although I am a Political Science major, there is a great gaping hole in my education where biology should be. so please keep your answer very simple.
I discussed the Paleo Diet with my doctor, and referred her to a few appropriate sites. She stated that she wasn't going to read through every post, but that there was nothing obviously wrong with the medical claims being presented and that if I wanted to give it a shot, there was no likely harm. She lacked confidence in the "healing power of ketosis" as she put it, but agreed that there was no evidence that ketosis was harmful.
One thing she did state, however, was that if I was going to buy into the ideas presented in the Paleo Diet, I should substitute Safflower Oil for Canola Oil. She stated that while she didn't necessarily agree with the ideas, people who DID believe that Paleo was the way to go would find even more of the things which they believe are particularly healthy in Safflower Oil than in Canola. Does this seem correct to you?