The Universal version of FCP/Studio will only be a straight port over of FCP 5 as it exists now. Nothing new will be added. If you are thinking of upgrading, stay put and use a version and machine that is proven stable. If you are just jumping into the market for machine and editing software, then wait until the Universal version comes out... and wait a bit to see if any bugs exist. As an editor nothing drives me up the wall like a recurring bug when I have a deadline.
My .02