If you are running OF 1.8, and don't mind a flattened list of your projects (ie don't mind temporarily hiding the folder structure), you could do this with an applescript along the lines of:
Code:
tell application id "com.omnigroup.omnifocus"
tell front document
set lstNotOnHold to flattened projects where (status is not on hold) and ((effectively hidden of its folder is false) or (its folder is missing value))
set focus of front document window to lstNotOnHold
end tell
end tell
And later restore the normal view (and visibility of folders) from the menu system with View > Show All Projects
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