I am a huge fan of Schafer, and so of course I'm looking forward to this game. But Double Fine? That's a different story. They are highly capable developers given their small size, but honestly it's unfair to rest everything they do on Schafer's shoulders. He's a great writer with an incredible creative spark, but he's simply not responsible for everything in his games and when it comes to quality of execution, far more of that depends on Double Fine than Schafer himself.
Considering all of the legal problems that Double Fine were going through during Brutal Legend's production, it's actually surprising it turned out as well as it did. Making games is far more than a matter of technology and concept, and everything from the coordination of a team, to budget, to time available, to marketing can enter the equation. It's not an excuse for a bad game, but when there's so many things that can potentially go wrong, I think it's unreasonable to expect every game from a single developer has to be a masterpiece.