What appears as "Status" in some parts of the UI is also referred to as "State" and "Workflow" in others. This is pretty confusing. "Assignee" and "Responsible" are less so, but the inconsistency is IMO unnecessary and best avoided. [[http://en.wikipedia.org/wiki/Conway's_law|Conway's Law]] at work?
"?" and "!" for type and priority in the issues list are a bit cryptic, as are the icons.