Look, we all know Fed likes to play. He's been known to say things like "I thought I set up the match pretty well" in interviews in the past (last year this was said I think during the US Open match where he lost to Novak because he was surprised by that crosscourt forehand winner and subsequent turnaround from Novak at match point). Basically, he expected another ACE victory with Novak letting that last serve go and bowing out. Unfortunately, he slapped the man in the face at the last second and while I personally think Roger was celebrating in his mind already, he kind of screwed himself by thinking Novak would not just try something.
That being said, it wouldn't surprise me one bit if Roger is sometimes just trying different things to extend a few games out and maybe sometimes just gives up on a set instead of killing himself to come back into it, knowing full well, he'll just break early in the next and try to run away with it. We've seen it before when he plays lesser players and while some can consider it dangerous to play with fire like that, I honestly think the man just likes to be out on the court a bit longer than he needs to be. I think he's comfortable playing 4 (non close) sets if need be. You generally don't see him mess around too much in other tourneys where it's best 2 out of 3. I think between last year and this year, we've seen him not mess around too much with higher ranked and dangerous players. In those instances, if he's too careless, he could screw himself quickly.
The other aspect is, he's making a lot of unforced errors (averages 40) in the past two matches, yet still wins. He said in the interview at the start of RG that he likes 3 out of 5 more because he feels that you can mess up a bit more and still dig it out. This proves it because in 2 out of 3 set matches where he's lost, he made those same kind of 40ish UEs and it bit him.
We won't know what happens with Novak and Nadal until Fed gets to that point in this tournament. I think right now, only the top 3 players are in a battle for themselves, no one else in the rankings is playing at the same level. Also, you guys need to remember the facts (and it has nothing to do with fannism or anything) but Fed's won the most titles this year out of the 3 top guys on tour. Sure, he didn't win a major title, but to have more consistant wins on tour than the other guys speaks for his abilities and skill. Bandwagon jumping fans, as I like to call them, keep hopping from player to player based on how popular or how many major wins they have in a year. I ask you this, would you rather be a constantly hot player for years or be a flash in the pan kind of guy? Novak is good, Fed is good, so is Nadal, but until their careers are over and you look at the bottom line of achivements, all arguments are moot. Enjoy your favorite player and go with that... but for once and for all, stop hopping on the latest and greatest. You're not a true fan of a player if you do that.