Okay, I have to admit that I've never sat through an entire viewing of the 1956 Invasion of the Body Snatchers or the 1978 version, so I probably give The Invasion more credit for originality than it deserves. But what can say? I love Nicole Kidman and enjoyed this movie.
The story and the characters all seemed believeable to me.
The movie's major drawback was its ending. [SPOILER! Highlight to view:] The unbelievable, everything-works-out-in-the-end was very disappointing. There should have been more sacrifices and more mystery.
However, I still enjoyed the movie and consider it one of the best of the year so far.