Great question, @Mr.JumpStart! And I am sorry I am not qualified to answer. The net present value of a pension is difficult to nail down: As a divorce attorney, I often have to hire CPAs to appraise pensions in divorce matters, and the calculations (which I am only very vaguely familiar with) vary greatly and can sometimes come to drastically different conclusions.
That's why for my early retirement calculations, like @EarlyRetirementNow, I just pretend like Mrs. Vigilante's pension doesn't exist; it's essentially a gigantic insurance policy for us should there be absolutely abysmal markets and horrible unforeseen expenses throughout our 30s, 40s, and 50s. Or beer money, as @FinancialRookie said.
I'll take copious notes on future divorce cases, though, so perhaps I can be of use relating to this question. In the mean time, I'll just defer to the other commenters!