The heavy-weights (sans Ebert who appears to actually enjoy movies) are pushing back against the early critical and popular acclaim:
A.O. Scott, NY Times: “The accomplishments of “Inception” are mainly technical, which is faint praise only if you insist on expecting something more from commercial entertainment. That audiences do — and should — expect more is partly, I suspect, what has inspired some of the feverish early notices hailing “Inception” as a masterpiece, just as the desire for a certifiably great superhero movie led to the wild overrating of “The Dark Knight.” In both cases Mr. Nolan’s virtuosity as a conjurer of brilliant scenes and stunning set pieces, along with his ability to invest grandeur and novelty into conventional themes, have fostered the illusion that he is some kind of visionary.”
David Edelstein, NY Mag: “Inception is full of brontosaurean effects, like the city that folds over on top of itself, but the tone is so solemn I felt out of line even cracking a smile. It lacks the nimbleness of Spielberg’s Minority Report or the Jungian-carnival bravado of Joseph Ruben’s Dreamscape or the eerily clean lines and stylized black-suited baddies of The Matrix—or, for that matter, the off-kilter intensity of Nolan’s own Insomnia. The attackers in Inception are anonymous, the tone flat and impersonal. Nolan is too literal-minded, too caught up in ticktock logistics, to make a great, untethered dream movie. … For the record, I wanted to surrender to this dream; I didn’t want to be out in the cold, alone. But I truly have no idea what so many people are raving about”
So Nolan has made another Dark Knight: a movie that everyone enjoyed, had great acting and cast, made truckloads of money, carries equal dollops of emotion and action, but apparently is still not considered a great movie.