I posted a new script over at VASST. I've used this for a long time and find it really useful.
Fade this event AND the event on the track below (audio) to black. Fade length is set using distance from cursor position to end of event that is under the cursor on the first selected track. If there is an audio track under the selected track, it is also faded. If the track below is not audio, nothing is done to that track.
The script is not earth-shatteringly wonderful, but it does make light work of a minor chore. It also reflects my belief that the cursor should be the center of focus when editing. When you have a lot of tracks, the cursor is the only constant across all those tracks. The intersection of track focus and the cursor should, in my opinion, be the focal point for all editing decisions made by Vegas.