My most recent cellphone purchase gave me video calling capability back in June. I used it once or twice, but haven't since. Part of the issue is lack of compatibility - I only have a handful of contacts who have similar capability. The other part is functionality; it just didn't work all that well.
This is, even when the technology is perfected (FaceTime is already damn close) and the user base grows, I don't see me using it all that much. As cool as the technology is, I just don't want people to see me all that often when I'm talking to them on the phone. My boss is across the country; we Skyped a few times when she first relocated, but now we just use the phone or IM.
My girlfriend, on the other hand, uses FaceTime all the time to talk with her distant mother, and loves it for that reason. So different strokes, I suppose.