Via Greg Mankiw, an updated list of the Thompson "citation laureates" is available on this link
This is a reasonably good snapshot of potential winners of the Nobel prize, which will be announced on October 11th. I have been predicting Ernst Fehr for a few years so I will stick with that, but Robert Barro and Paul Romer must be approaching a nod. Matthew Rabin is also on the list. I am not sure why Andrei Shleifer is not on the list as he is the top cited economist on the IDEAS citations rankings which are here. Given his productivity in recent years, the panel may have to decide at some stage whether Heckman merits a second prize. All of the people on the Thompson list could be in there in October. People like Tirole and Deaton are also still in the long list on IDEAS. Schliefer, Barro, Gertler, Blanchard, Levine, Acemoglou, Tirole, Stock and Mankiw are top IDEAS cited researchers who have not yet won the prize.
Given the decisions in recent years to award prizes to people from the interdisciplinary boundaries of Economics, it is always possible that the prize may go to someone people were not expecting. It seems intuitive after the fact, but I don't think anyone could have predicted Elinor Ostrom last year. The philosopher Jon Elster has made such a profound contribution that he could be a surprise outside bet. I am sure that there are others in fields like economic history, political science and related disciplines that have had profound influences on economics that may also be potential surprise winners.