Sorry for the long time without answer. I hope you guys are still interested in.
I managed to add what we are discussing here: http://pkp.sfu.ca/wiki/index.php?title= ... sion_lists
I think that what we propose here will list all submission within the system, except the archived ones. But we don't add the dates that you added. I think that's important for editors that really needs to take an action on that submission, but then you will have your task list that will show you a direct notification that you have to do something. We don't have dates there, maybe it's a good idea to add there.
Our proposal it's different than yours because it gives users 3 grids, so they can have a quick look to submissions at 3 different perspectives at the same time. It's easier for an editor to check for an unassigned submission and at the same time see how many submissions he has, or check for editors with less submissions assigned.
Let me know if you have any ideas or questions. I am more capable of working on this now.