Basically, each project gets it's own set of open files (tabs). Maybe in option to allow this behavior.
So if I go from project 1, which has 4 files open to project 2 which has 6 files open I can switch between the two and see only that project's files. This way I don't have to have 10 files from 2 different projects (sometimes of the same name) open all at once.
Very helpful when working on multiple projects.
Thanks!