I went to see this at the cinema last night with my housemate Matt, and it was utterly amazing!
Definitely worth seeing at the cinema, I'll definitely get it on DVD but I really don't think it'll be the same!
The ideas behind it were fantastic and I love the slight ambiguity at the end. It's one of the first films in a long time to actually make me jump, lol, only once, but it did... It's true I don't watch a lot of thrillers, but I thought this was really excellent. The phrase 'on the edge of your seat' was certainly relevant for a large section of this movie.
I love how you get into it so much that you forget which dream is which and how many levels there are...
Also, you do come to care for the characters pretty quickly, and they have depth (this is particularly explored in the case of Cobb).
I've wanted to see this ever since I saw the trailer, I knew it'd be excellent (plus, I love almost anything with Ellen Page...)
I just thought I'd put this up here and encourage people to go see it at the cinema before it stops showing! So worth it :).