I don't think it's to soon at all. In fact the oposite. The stuff is still fresh in our heads, and personally I know MANY people who have to take the LSAT more then once. I somewhat expected to re-take it in Feb anyways and looked at December as a warm-up or practice. Now we can see were the weaknesses are and focus on them.
Being realistic of course that hardly anyone jumps from 150's to 170's of course, but every point makes a difference, so go for it.