Sharp lenses make sharp images... put your money in the glass. Also DSLR produces a great image in low light and you have the bonus of a creamy archival quality image that doesn't look flattened out. My experience is that a wedding is a staged event and with planning and use of jibs and sliders you convey much more of the emotional aspect of the event than with zoom on the fly. 
Doc producer: T2i, T4i, 60D, Ex1, Ex3
You can put Zeiss cinema glass on a T4i and I guarantee you it will never be as sharp as a comparable camcorder. Why? Simple. The sensor has no idea what a 1080P image is. The processor uses extremely crude line & pixel skipping to simulate the 5,184 x 3,456 sensor as a 1920x1080 sensor.
If you were to grab the centermost 1920x1080 sensor data, you would have your moire-less, tack-sharp HD video. The problem is that you'd also be stuck with a ridiculous crop factor that wasn't very useful.
Now, if Magic Lantern was able to change how the raw sensor data was captured, say for example, you pulled the center 3840x2160, then threw out ever 2nd horizontal pixel and every 2nd vertical pixel, you would have a much cleaner image and you would only be dealing with a zoom factor of 26%. This would also reduce the rolling shutter considerably, because a smaller area of the sensor is being refreshed.
