Kinect in ME3 is still just a rumour though, and even if it wasn't they have already confirmed that Skyrim will not support kinect. Motion control is a silly gimmick, and one that will hopefully die out sooner rather than later.
I strongly disagree with this sentiment. Games like Skyrim are the ones that would benefit
most from Motion control, especially if implemented for combat. It would be a more engaging experience, being able to intuitively control weapon strikes and position. But, it would be difficult to program the go-between to smooth out the differences between what is recorded (At 1:1) and what is performed (smoothly removing 1:1 to moderate weapon and movement speed, handle assorted stuns, handling interrupted actions, and smoothing out animation), so it looks like a believably competant fighter using real, weighted weapons and shields, instead of a nerd in a cool-looking suit flailing around with nigh-massless props.
Being able to control footplay, dodge directions, shield position, and the directions and manner in which you strike would be great for combat in an Action-Adventure-RPG. The control and versatility in control in combat and style of a fighting game, without the complexity and need for stupid amounts of buttons and keystroke combinations.
However, the game would have to be built around the motion control, as others have said. Wii Motion Plus, Kinectm and Playstation Move aren't gimmicks in themselves, but they've only had gimmick implementation. Right now, they are just wasted potential.
The biggest problem with Kinect is the software to support it is competing with more tangible content on a very limited disk space and a very small processor... The 360's expiration date was 2008, and now Microsoft is holding the industry back.