I wouldn't say "merging," more like sharing. Just as most of the camcorders can do stills, the DSLR's are now going to have video capabilities as an extension of the liveview. Regardless, as you said, the true videographers will buy a camcorder and the true photographers will buy a camera. Having one that can do some of the other is not a bad thing... and inevitable.
Regardless, this is a thread about external microphones.
My friends were messing around and took this.
If you crank up the volume you can hear hands moving on the camera (for zooming in) and the IS motor. Without the external microphone, you hear mostly IS motor and the voice is much more tin can sounding.