No, I won't be giving away any plot details, because I respect Christopher Nolan's artistic ambition too much to do that. Saw it Friday night with my spouse and we were gasping and questioning each other throughout. Have no illusion, this is a complex film with a narrative that demands focused attention. I suggest going light on beverages to avoid the confusion that will come with 1-2 bathroom breaks over this 2:38 film. Then be prepared to be haunted long after by several of the expansive concepts pursued in the film--several of which have informed nightmares throughout my life.
Surest sign that I loved it: I purposely didn't bring any kids along, because I want to go back with them individually and see it again. This is coming from a guy with a better home theater experience than what I can get in theaters, so it takes a great film for me to go back more than once. A clear best-pic nom and multiple others, to include best original script (one that has been bouncing around in Nolan's brain for a decade).
[Note added late Saturday night: I did indeed go back and see it for the second night in a row, something I've done with maybe 5-6 movies in my life, the first being "Apocalypse Now." I was surprised at how well my ten-year-old could follow it, but he's awfully smart in that way--thanks I think to a lot of good books and complex narrative navigation in videogames. I liked it EVEN BETTER the second time!]
What I liked: A bit of return engagement for DiCaprio, meaning similar to his role in "Shutter Island," but he does that sort of stuff so well (confused character with tortured soul) that he's a joy to watch as he ages. Ken Watanabe also fun to see, and Ellen Page likewise great. I especially liked the Brit, Tom Hardy, who's a glorious character. Michael Caine in a bit role, and Marion Cotillard frighteningly luminiscent.
This film has horror, psychological tension galore, action sequences to match a Bond film, head-spinning visuals, but most of all it has a brain. Nolan delivers something incredibly rare in moviemaking: you really are pushed to examine yourself and reality throughout.
The film should be viewed in light of his previous efforts ("Memento" and "Insomnia") to explore the theme of sleep, perception, reality, etc.
Nolan is this era's Philip K. Dick and he should be appreciated as such.