The ability to save a certain output/job to disk.
We typically print all films in a job at once, and on reorders being able to just open the file
in Film Maker would save us going in to Illy to open the output file.
I believe it's once you rip a job you can right click and 'archive to disk'.
Pain in the butt, and the dialog to open stuff is hell, and they could certainly throw the standard windows dialog in there so you can actually make subdirectories and such, but it is technically there.
Personally, the only improvement I'd like to see is better reliability, speed, and stability.
New features are useless without reliable core functionality.
A huge number of software companies could use that advice though...