I'm pretty disgusted at this Cameron hating. He's one of the best directors out there and hasn't made bad movie yet. Why assume he'll start now?
I'm not so sure I'd classify much of the criticism as "Cameron hating." It seems to me that much of the critique stems from a letdown (admittedly from a mere teaser trailer) from the hype. Nothing in the trailer seems to point toward a "revolution" of any kind and considering the fact that Cameron hyped his film as such, he opened himself up to that kind of critique.
Personally, I like Cameron's films -- even went to see Titanic opening day because I thought T2 was such a blast. But considering the lack of "wow" to the visuals (relative to the hype), it's only natural for some (like me) to voice their criticisms.
I hope the film succeeds. I hope the visuals turn out to be far better on the big screen and in 3D. I hope the story is compelling enough to warrant such extravagant visuals to begin with. But even though the trailer doesn't suck, it just doesn't inspire that kind of hope, either.