You know, @Geo and I disagree about a lot of stuff, but damn was be bang-on the other day when he said that the death of Metallica happened when James "broke." That is exactly it. He nailed it.
James changed pretty fundamentally sometime in the late 90's / early 00's when he went from being a snarling, raging, piss and vinegar fueled machine to a totally pacified, subdued, gentle kind of dude who seemed like he'd be the kind of guy who gets up early to go bird watching in the park for fun, right after he writes a paragraph or two in his gratuity journal. No idea what happened specifically, but everything about the band changed at that point. I even think the attitude was still there during the Load/Reload era, and even going into the Garage Inc. album. But then, James went from being the guy creating all the mayhem to the guy standing outside looking through a window at it like a tourist. Then they hired the smiling, goofball ass, gorilla waddling Robert Trujillo as Jason's replacement, and the band's changed tone was pretty much cemented from that point on.
At this point, Metallica just sounds like a "hello, fellow kids" type of second rate cover band. Yes, bands change and evolve, but a lot of bands at least maintain some kind of their original spirit. Metallica has not maintained any of that original spark at all. They have lost it completely, at least for me. To me, they don't sound like they're "evolving" anymore, they sound like they're trying to be something they're just not.
I'd rather have 10 more Load / Reload clones that are slower and more rock than metal, but at least have some kind of genuine soul and attitude in them than a single other Death Magnetic / Hardwired / 72 Seasons disjointed cutting room riff floor salad "haha we're definitely still a thrash band this is fun!" type nonsense.
Then again, maybe the bigger (and much more horrifying) problem is that there is nothing to "recover" under the surface any longer. Maybe they are making genuine music for them right now, and the real issue is that their art is simply no longer interesting because they have nothing left to say, but they're just still making music because that's all they've ever done and hey, people have to do something, right?