Not neccessarily. I don't think the jab was the hallmark of Hopkins performance, though he did land it. The point was his movement completely offset Pavlik, so he could outjab him if he chose to, or just do anything he wanted. It will depend on how Williams moves, if he stands in one place and simply trades that will be dangerous. If he can keep up his activity but move and pivot, show different angles, he has a great chance of confusing Pavlik.
This is a two edged sword: The jab is the most important punch in boxing, as I'm sure most of you know. Paul should try to use a good stiff jab to keep Pavlik from coming forward at will; snap it hard and move. And, use it as a range finder, and try to use it to set up big lefts. However, if I were training Paul, or any other fighter, to fight Pav, I would tell them to avoid getting into a jabbing contest with Kelly. Pavlik is no speedy-slickster, but he's pretty damn tricky with his left hand. He taps with it, he throws it like a sledge hammer, he throws it into the eyes with an open glove, and he turns it into a hook at the last instant. Watch rounds 4-7 of Pavlik/Taylor I, and you'll see a good example of what happens if you get in a jabbing contest with Pavlik.
Williams has been adding to his game as a boxer with every fight. There was a time when he couldn't sit on his punches or throw a non telegraphed punch, now he can. It's only a matter of time before he learns to use his height. No it has nothing to do with him being "open", Roy Jones Jr was open when he fought a very similar fighter Jeff Lacy. Jeff didn't know whether Roy was coming with a hook, a jab, an uppercut, or how much power would be behind it because Roy Jones Jr doesn't telegraph AT ALL. The reason Roy could look into the crowd and still dodge Jeff Lacys punches is because Jeff Lacy telegraphs all his punches. This is why none of his punches land clean and it's the same thing Mayweather does and everyone say he has great defense, or Vitali. It's not because they keep their hands up more, they just know what punch is coming and when. Someone said Williams shouldn't make it a jabbing contest and I agree, the jab is about the only punch that Pavlik throws semi telegraphed, everything else is completely obvious. He does telegraph is jab though, watch his legs.