So this is kind of a long time coming, but I added support in the program for Master List querying. If you go into the Tools option on the toolbar you can pull up a master list subwindow. Within that window you can select a system and it will pull up a list of all the games for the system both released and unreleased. Filtering the list can be done by typing in the text box below it.
I also added the special composite list type. Essentially that list type serves as a list that carries none of its own date, just a compilation of data from other lists linked to it.
If anyone is interested, you can find it
here.
EDIT: Just downloaded it on my work machine and ran it in Windows and the GUI looks all fucked up, I'm going to have to try and figure out a way to make it look the same in both Mac and Windows.