We use 1 pipe for on-site industrial work.  A Date range field option would be helpful.  Currently we have to use 4 different date fields to try and get all the data on the card that we need.  Also some sort of calendar view by month based on the date ranges, like a Gnat chart or work load chart would be tremendously helpful for us service based companies.  

We are currently using the 4 date fields for Project start date, project completion deadline date, and 2 milestone dates in the middle.