I assume there will be injuries. There are injuries when you have very skilled people trying to do this stuff. I too hope they won't be serious in nature. The ones I worry about the most are the female pros who are getting lifted by the amateur "stars". They are the most exposed to really serious injury - especially if they push the limit in an attempt to get higher scores. These pros will be trying to establish themselves in the circle of bankable talent and might therefore be more inclined to take more risks than an established pro with a household name.
On another topic I am curious what they will do about music. I hope they use pre-recorded music as opposed to further employing the DwtS band.