Well, I just got back from seeing it in 3D and I'm ready to side with Bube.
I'd say it's about average at best. I went because of the visuals and I was still disappointed by it. Many friends had said how much they got sucked into the world of Pandora, but I can't say it worked for me.
Okay, first the story/screenwriting, etc. You guys have pretty much covered it, but I have to reiterate that it was taken out of the screenwriting 101 text book. Does that make it bad? Not necessarily, but cheesy lines and a predictable story arc and completely one dimensional characters are boring and uninteresting. Again, it did the job of getting you to more action scenes and fireflies flying into your eyeballs, but I never really cared about why it was happening and that's a pretty big failure.
One more thing about story. My film teacher used to say, "Every movie you'll ever see is the same. Boy meets girl, boy gets girl, boy loses girl, and then it's all about how you tell the story." Well, I thought Avatar's was too simple. Also the "pre-war" speech was straight outta Braveheart
Now to the visuals. This is easily the most impressive CGI I've ever seen. There are probably a lot of technical aspects I don't understand, and many things looked very nice. In the end, I hated the general color scheme. Everything had that weird neon glow stick look, I just kind of got sick of it. The creatures were okay, but everything was slimy, there wasn't that much variety in the world of Pandora. The action scenes were great and half-way through I just kind of found myself waiting for them and nothing else, but you can't have just a movie with action scenes.
Anyway, I expected to be blown away, and I wasn't.
People keep saying that this movie will change the industry forever, but...really? Is that it? I'd still rather see Miyazaki's beautiful 2D drawings and the world/story he creates than Cameron's any day. Or Pixar for that matter. They create brilliant and beautiful worlds around a great story rather than the visuals like Cameron seems to do.
Anyway, so I'm with you, Bube!
PS: I didn't really see the Mid-East connection until these blatant lines.
General Whatever: WE FIGHT TERROR WITH TERROR
Doctor Whatever: They're starting some "Shock and Awe" campaign
That last one especially is a pretty direct reference to the beginning of the Iraq war.