I currently quite often extend my queries in the "All" category with "-owner:myusername" because I know what changes I have pending and want to know what else is going on (and I often have many changes pending which then clutter the UI.)
It'd be nice to have an "Others" top-level, aside with "All", like this:
All | My | Others | Admin | Documentation
where in "Others" "-owner:myusername" would always be part of the query (if I add it manually it's not carried around when I click on something to fine-tune my query)
To implement this, and also to make the manual queries easier, it might also be nice to have something like "owner:self" (although this might conflict if somebody uses "self" as a username?)