As I was walking into the movie on Saturday night, R sends a sms "P & I just finished watching Inception. We reached consensus that there is too much hype. It's like Thirteenth Floor meets Ocean's Eleven."
Inception is not the most original movie around. Lots of movies and stories previously have made use of layers of dreams and reality. The Matrix for example, is a very easy example of such a concept, and science finction stories exploring "other worlds" (e.g. Narnia series) feature distrotion of time, and the inability to separate reality from the dream state. Sergey Lukyanenko's Night Watch series also features layers of "Twilight", separating reality and the magical realms; but also feature the distinctions used in Inception - the distortion of time and the the ability to influence the outcome in the real world through actions in the dream/magic world.
That said, Inception is a very polished movie with a very good script (when compared to many Science Fiction and Fantasy stories); although there are some very glaring plot holes. The mechanisms of the heist, and for that matter, the inception at the heart of the story, is well thought out, and cleverly written. And unlike many heist stories, where there is a clear winner (either the thief wins with our support, e.g. Thomas Crown Affair or Ocean's Eleven; or the heist is foiled, and the theives are brought to justice), there is no real winner in Inception(and for that matter, there is no clear moral position on which side the audience should be supporting either).
Is it worth the hype? Yes - partly because of the lack of really good movies this year, partly because of the good acting (another rarity in Science Fiction/Fantasy movies), partly because of the polished production. In terms of Christoper Nolan's movies, this is not a classic like Memento or The Dark Knight; but rather like The Prestige - it is good, but not great.