A common scenario is "Show me all the things we need to work on, order by priorities and due dates"

Unfortunately the current limitation of JQL is that when you order by a field in descending order, Blanks / Nulls appear first. While this makes sense in some scenarios ("Hey, this doesn't have a due date set - set one!") it doesn't when not all tasks have a due date.

Suggestion: Enhance the JQL Spec to add "blanks last" and "blanks first". I used "blanks" instead of "nulls" as currently "where <field> is null" is actually "where <field> is blank" in the JQL language.