Well, if you figure one of the common interview questions is "where do you see yourself in 5-10 years" ~ thinking up an answer now and putting it in your personal statement wouldn't be a bad idea. I was told the same as kem (to talk about career goals in the personal statement) so if you see yourself doing a fellowship, I don't think it would hurt to mention it.
I'm such a deliquent. I know I should be working on that personal statement...instead, I keep taking naps!