Yes, Next Actions are project agnostic.
Think of Next Actions as a shopping list. You don't create your shopping list by recipe (seperate list for each recipe), you create it based on the fact that you'll be in the supermarket. If you're really savvy, you create the list based on supermarket aisle.
Similarly, Next Actions should be sorted (if at all) based on situation. Things you can do when you're @phone, @computer, etc. I suspect 99% of the people don't need to do this because they're not on the road all the time. When you're at your desk, every tool you need is there with you.