The shooting in PES 2010 was pretty straight-forward but in this years edition, it is MUCH more complex. The game seems to be very challenging so far, and shooting is the main suggesting aspect. Although most less patient PES players will find this as a problem, I feel it's a good thing.
In recent years, the shooting was very predictable. Last year, I played so much PES that I knew what was going to happen, before it happened - depending on where I shot from. It's hard to explain but if you played enough PES 2010, you will know what I am talking about.
However in this title, the shooting system seems much more unpredictable. But that's a realistic thing to be honest. Players shoot not knowing whether they'll score, just like in real life.
Saying that, the shooting system isn't agreeing with me at the moment. But with like any PES, it will just be a case of waiting - and practice, practice, practice.