Honestly it's hard to predict that far out. I would guess that due to retirements, global pax growth, and poor compensation packages there will still be a decent demand for pilots over the next decade at least. There may be ups and downs, but if you hit a down cycle 2-3 years of CFI and/or 135 would probably be the worst that would happen...which is still better than what most civilians had to do in the 80's and early 90's.

War, economic catastrophe, or high oil prices could screw this up of course.