I really have mixed feelings about this. I like Tom Cruise and feel that he's actually a really good actor who makes great action movies. However, I've been reading the Reacher books for about 10 years now and every book plays up his size (6'5, 50 inch chest, ex-military). Reacher's size is so integral to the character. ~80% of the books are written from Reacher's perspective and you get to see how he uses being so much bigger than everyone else to his strategic advantage. I don't know how that's going to play out on the screen and feel that the movie's Jack Reacher is going to be quite different from the book's.
Meh. I'm open-minded.
Hopefully the screenplay will be awesome and I'll forget that Tom Cruise is certainly not how I pictured Jack Reacher.
ETA: The majority of the books are written in the third person not the first person. D'oh!