One of the biggest design changes Canon's made to the body of this series is the locking mode dial: you press the button in the center to turn it. Unfortunately, I find the method relatively awkward compared with Nikon's approach (although, to be honest, I've never had problems with unlocked mode dials as some other people have).
And the use of a movie mode--as opposed to having a dedicated button or switch--is just plain annoying. Especially since it's on the exact other end of the dial from the other modes you're likely to be using. It wouldn't be quite so onerous if the dial rotated 360 degrees. But it doesn't.