[Greg Jones]

Why not just set your Context view preference to 'Available'? You'll still have only the unblocked actions on sequential projects and all available actions on parallel projects. My understanding of the 'Next' action only preference was for people who want to impose a priority system on parallel projects and really want to narrow the focus to the highest priority item on the list. For a more GTD approach, 'Available' should do exactly what you want-yes?