[Toadling]

I assume you're talking about lists in context mode, since items can be manually reordered in planning mode.

Maybe this isn't exactly what you're looking for, but if you set the view bar to unsorted in context mode, the order of the actions is determined by their order in planning mode. Does that make sense?

Again, maybe not exactly what you wanted, but it's a start.

Maybe OmniFocus could have a "Manual" option in the sort menu of the view bar? Switching to that option could allow you to sort in some arbitrary order.

-Dennis