Nadal did well so far in Wimbledon, that's true. He won with maximal 3:0 in the first three rounds against Michael Russell, Ryan Sweeting and Gilles Muller, then 3:1 in the next three rounds against Juan Martin Del Potro, Mardy Fish and Andy Murray. Nadal also won three tournaments this year. But, he managed to win the tournament only if Djokovic wasn't there (Monte Carlo and Barcelona) or if somebody else eliminate Djokovic before (Federer in Roland Garros). So, Nadal has no luck here. Djokovic became a nigh mare for him. Djokovic won the last four games against Nadal. All four were the finals, which is very important. Just look the results:

15.05.2011. Rome, Italy (Red clay) Nadal - Djokovic 0:2 (4:6 4:6)
08.05.2011. Madrid, Spain (Red clay) Nadal - Djokovic 0:2 (5:7 4:6)
03.04.2011. Miami, USA (Hardcourt) Nadal - Djokovic 1:2 (6:4 3:6 6:7)
20.03.2011. Indian Wells, USA (Hardcourt) Nadal - Djokovic 1:2 (6:4 3:6 2:6)

I must admit I don't understand the bookmakers. Djokovic has an excellent record against Nadal this year. In fact Djokovic is incredible this year, he has just one defeat the whole year, from Federer in Roland Garros semifinal. From tomorrow Djokovic will officially be number 1 in the World, no matter win or loose here. And the man who lost that first place on ATP ranking is exactly Nadal. It is a big psychological advantage for Djokovic, I am sure about that. So, I believe Djokovic is closer to the fifth consecutive victory against Nadal. Because such psychological things will determine the match, not the current form (both are excellent) or some tactical surprise (both know each other very well). I expect Djokovic to show why he is number 1 in the World at the moment.