maybe somethng with a MSVC style file viewer to the left that if you double click on any of them an apropriate editor pops up,
it would list all files visable to FS includeing files in VPs and suport the editing of files within VPs, it could be structured in one of those tree thingys were if it is in a directory or a VP it gets a diferent icon for it's parent node, you could drag and drop files from a directory into a vp or vice versa, useing the right mouse button would give you the option of moveing or copying, left would just move (or copy, maybe have this setable from an options menu), you'd need to suport all file types includeing graphics (pcx, tga, anyhting else FSO may suport in the future), mission/campain files, ANIs, TBLs, and POFs