Not without a significant board redesign. The other problem is that you generally want the transmitted (from the phone) radiation to emit from a point on the phone as far away as possible from the human head. The FCC doesn't exactly require this, but most every manufacturer does so to meet the SAR requirements. Another issue is that the antenna lengths matter to some degree. (Though not as much as some think, because the antennas are by design, very broadband. They're not the old-fashioned "resonators" that some might imagine).
In short, there were a lot of engineering challenges that had to be overcome in developing the iP4. The antenna is in large part, an engineering tradeoff most likely with the benefit of a much bigger battery. Apple is probably reevaluating these tradeoffs and determining how to make the antenna less susceptible to touch. But, any change is going to require quite a bit more engineering time.
Oh, well I hope they don't change the design to much. I like the look and feel of the phone. Maybe they can resolve the antenna thing w/out changing the overall design...