The ability to use normal search and have it shown in the format that the References tree shows, organized by file and function/area it is in. This is often significantly more helpful to me than seeing the line itself. Results found in comments would be new work but I think this would be an awesome feature.
SE does this already when you Find References but the symbol is not found. A message pops up and says that a search was done instead and shows the nice tree under References.