GTD: Projects, Someday/Maybes, NAs
Projects lists should only contain those things that you need to deliver on in the next 9 months. Deliverables beyond that belong on your 'Someday / Maybe' list and can be turned into Projects when they fall into the 9 month window. If you include a review of your Someday/Maybe list in your weekly review, you won't miss the projects and you can get them off your mind.
Next Actions Lists should only contain NA's that you plan to complete in the next 2-3 weeks. Note other actions that you think of during the weekly review in your project support material and turn it into a next action when needed.