29351 and enaires make good points. The GPS is only an aid to VHF nav and the decision to Jump/Not Jump is still with the meatbombs.
I once plotted a GPS waypoint off a VTC which at best would probably give me an accuracy of 1/4 of a mile. At the time I was flying VFR on top with plenty of breaks around (except over the DZ) result being that 10 skydivers blindly leapt out with a number of them in the drink.
Still maintain the best response I received when I pointed out that we had no DG or AH and could not consider any non VMC flight was: "So what, You've got a GPS havent you". Take note Jerry, that is the mentality you will be dealing with.