The Canon 70D has a very unique dual pixel AF sensor system that is able to split each pixel for autofocus. This really improves the way that the AF performs when you are in both in live and movie modes.
Canon has a video entitled “Handmade” which is done via 70D. This is available as a part of the launch and shows the new AF system that the 70D has. It also shows another video that goes behind the scenes. Hopefully, we will be able to review an actual 70D soon; however, until that opportunity comes along we will just have to settle for watching the launch video. This particular launch video has an up close look at what the AF system has in store for you.