I, too, did it in 2010. Did the initial 3 years, and then got a one year extension (after MUCH admin effort).
I got hit with a non-flying Chief of Plans to Balad less than 3 months after signing up. Of course, I expected it. But I was able to horse-trade it for a deployed MC-12 flying position. The MC-12 program was a mess,... but I digress.

No guarantees then... I would be curious if they consider some guarantees for the future to sweeten the pot. They will need to.