Keygrip,
I don't think that there is a small aircraft out there that can't get airborne prior to the spot where the large aircraft rotated, so the caution wake turbelence is given to ensure that the pilot is aware of the potential of wake turbelence, and to plan their rotation and climb out accordingly.
If a pilot in a small aircraft wants to wait a minute or two, then they should tell ATC prior to going into postion onto the runway.
From what I was trained, in the above situation the pilot will make sure that he gets airborne prior to the spot where the large aircraft rotated, and climb so as to stay above or off to the side of the large aircrafts flight path to avoid any potential wake turbelence.
Mike
NATCA FWA