I don't know that there are any must have features here for me compared to the 60D. It seems like the improvements are largely incremental. The wi-fi is a nice add. The AF is improved. It's a bit faster and probably a bit better in low light. The Dual Pixel is great for video and live view photography. I rarely do video and I stay away from live view photography precisely for the reason Dual Pixel is supposed to fix, so that would be something I'm interested in. But...
... I am so irritated by some of the other "improvements" that I'm turned off by this camera. Specifically, why do camera manufacturers feel they have to rearrange all of the buttons on the back of their cameras every time they come out with a new model? There are 11 buttons on the back of the 60D. Five of those buttons moved and one button was replaced by a switch. I'm happy with the replacement of the control wheel lock button by a switch (it is a horrible little button that I can never find in the dark) but the relocation of the five buttons serves no apparent purpose other than to confound photographers who are used to the back of the 60D. This is a big deal if you shoot with more than one camera in your bag. I would much rather buy another 60D than upgrade to a 70D. The aggravation of dealing with two different control interfaces is much greater than the incremental improvements the new body adds. I would only get the 70D if I were buying 2 of them.