Rafa of 2008 was still running for everything.  Now he thinks before going for a low percentage winner.  Rafa is slower  off of the mark and he knows that any extreme moves may result in injury.  He's like bad back Agassi only not quite that restricted....yet.  Can still do everything except make improbable winners.

PHM is dump and nadal is real value at 1.1

he wins in 3 sets forget about that

Big difference in his mind not just body imo, easier being number 2 than number 1. What made Pete and Roger so great was how comfortable they were with being on that pedlar-stool at the top of the game.

Players play fearless against him at the moment, going for winners. More importantly he does hit the ball flatter than a year ago, less topspin. Some say because his earlier play caused him to lose the FO to Soderling. This results, however, in him being more vulnerable now to other players aside from Soderling.

I really don`t think there is any need to put too much emphasise on the Lopez defeat, best of 3 on grass at Queens often the difference is one or 2 points especially if the lower ranked player is playing a great match.
The difference between 2008 and 2010 I think is simply no more than that 2 of Nadal`s 3 opponents so far have played the match of their lives, at least to this point in their careers. It happens, unusual for 2 in  row though in the same tournament.

Remember Cowan v Sampras? It happens, but who won the match is what counts.

doesn't get to as much as he did before 2009

Not suprising if the  performance of his opponents is opponents is of a higher level compared to 2008. I don`t think either of his 1st 3 round opponents played as well as Haase and Petzschner.

R128      Andreas Beck (GER)       122      W 6-4, 6-4, 7-6      Stats
R64     Ernests Gulbis (LAT)     48     W 5-7, 6-2, 7-6(2),6-3     Stats
R32     Nicolas Kiefer (GER)     32     W 7-6(3), 6-2, 6-3     Stats
R16     Mikhail Youzhny (RUS)     17     W 6-3, 6-3, 6-1     Stats
Q     Andy Murray (GBR)     11     W 6-3, 6-2, 6-4     Stats
S     Rainer Schuettler (GER)     94     W 6-1, 7-6(3), 6-4     Stats
W     Roger Federer (SUI)     1     W 6-4, 6-4, 6-7(5), 6-7(8), 9-7

the courts are a lot quicker

The courts do appear to be a little quicker this year or perhaps I'm imagining it. I can't imagine they really changed much.

The real difference? Dr Fuentes is on vacation.

"More importantly he does hit the ball flatter than a year ago, less topspin."

He's doing this to shorten the points and spare his body.  So he'll net more backhands.  Real strength of the Nadal game was consistency and great defence because of his speed. But his biggest strength was and still is his mental strength. 

Last match he showed uncharacteristic anger and frustration.  For good reason of course.  Two guys he should be able to whack take him to five sets and his knee is bothering him.  He's not Federer.  He doesn't like low ranked players jerking him around, even in a losing effort.