As someone entering the legal profession (but not there yet) I don't feel comfortable offering my opinions on issues like this one.
But, even in the driest legal sense, my first reading of the partial birth abortion decision sounds a new note in abortion jurisprudence. I encourage you to read the decision (along with the concurrence and dissent).
What is so shocking to me is that Justice Kennedy, writing the majority opinion, goes to such great lengths to explain the various procedures at issue in the opinion. It is not for the faint.