OK, so build a new system, a superset of MUMPS that adds the needed functionality but continues to support the legacy code as well as some newer, better syntax.
That way you can transfer in all the old crap and replace it bit by bit over some time. I'm sure I've even seen technology that analyzes executables and re-factors them - perhaps similar techniques could be applied to the old MUMPS source. Sure it's hard, but with $9B and several years I'm sure a handful of CS guys at a university department could achieve something truly exceptional.
I was 250, got down to 210 in a zealous fit of diet and excercise a couple of years ago. I seem to have settled at around 230 now (still obese, I'm not sure that label is helping me). I have gone back to not eating well but I did at least find a sport and stuck to it, so some good did come out of it and I feel a lot better than I did.
What I want OSU to do is to come up with something that means I can continue to eat badly but not suffer the bad effects, it's not that I don't know how to eat well or that I don't enjoy health food, it's just that I enjoy the unhealthy food as well. I found it far easier to change my excercise habits for the long term than to change my diet habits