The phrase “Case Web” springs to mind, but essentially it’s a spider diagram that would allow zooming, dragging, etc. Look at www.geni.com and you’ll see what I mean.
I’m thinking literally small boxes with the case number in (hover over and you get the mini-preview like in the single case view) with lines joining them together. I might try and knock up a desktop app as a prototype to see how it looks.
Also, I’d really like to see the concept of packages of work in FogBUGZ. A release may contain a number of cases, but a group of those cases might be the “new editing screens” cases, and the only way I can find to link them together is to add “case xxx, case yyy” etc to every case in the group, which is unmanageable when you want to add a new case to that package of work. Am I missing something?