The ability to filter items by status is really important. You have the capability http://screencast.com/t/cEwllqJsH ! But I have a suggestion to improve the usability.
If the options in the list were in a visual hierarchy and you said "open" rather than "opened" I think it would be a much quicker job to comprehend.
Open (13) (every ticket was open*ed* at some point)
Under review (4)