I dont see why a Nadal fan, or even a general fan, is wrong for thinking Nadal has a good shot at both the French and Wimbledon last year. Yes he ended 2011, which wasnt that as bad a year as some potray, on a low note. However indoors is his worst surface at the best of times, and it is natural his confidence is probably shaken a bit now. However if Djokovic continues to show he has hit a brick wall for the moment and stumble around, that alone will give Nadal alot of confidence back. Plus he is a fighter, he will continue looking for ways to counter the new and improved Djokovic. In any case:
French Open- Yes Djokovic is a threat to win the French based on his wins over Nadal on clay this year. However he has always underperformed at the French. Amazingly he hasnt even made 1 final there, including last year when people were ready to hand him the title, and in 2009 when with Nadal's huge upset loss and having beaten Federer on clay earlier that year it was wide open for him to win. Federer could barely ever beat Nadal on clay even in his best years, let alone now, and failed to do it last year when Nadal was low on confidence, and when Federer came into to the final on fire and very determined to win. Murray on clay is not a potential champion at all. Del Potro isnt back to the level to even win hard court slams yet. Nadal has only lost 1 time at Roland Garros for a reason.
Wimbledon- Djokovic won last year while he was in the form of his life, but grass is still his worst surface. Unless he is in the same incredible form as last year, it will be hard to win back to back titles on his weakest surface IMO. Murray is better on hard courts but good enough on grass to win if he can overcome the home court pressure, but he cant even handle the pressure on neutral territory yet, let alone adding the home country factor to that too. Federer has declined most on grass of anywhere, he isnt winning here again IMO, I would even give him a better shot at winning the French again than Wimbledon at this point. Nadal has made the finals everytime he played since 2006 for a reason and there is no longer prime Federer to stop him, so unless Djokovic can continue regain his career best form Nadal has a great shot here too.