I loved this movie. And I really want to see it again. It just got into the cheap theatres here in town, and I think I might be going tomorrow. Two dollar Tuesdays. Beautiful.
As for the ending:
*Spoilers*At the end, Philippa (Cobb's daughter) was in a very slightly different outfit. Before I saw the movie, I was told to pay attention to the kids' clothing, and so my friend and I (we were told to watch the clothes by her sister, who wasn't sure how to interpret the ending, but thought there might be something to find in the clothes) paid attention to the outfits.
Throughout the whole movie, whenever Cobb saw his kids in that dream-state, they were always in the same outfits. At the end, his son was in the same clothes, but his daughter had a white tee under her sleeveless red dress, which had capped sleeves and no white shirt every other time.
To me, this difference plus the fact that he saw their faces, indicates that it wasn't a dream.