I think the best outcome will be there's no change to the GOM's financial benefit where the IA is concerned. The terms of the IA to this regard should stay the same, or the future of foreign investment in Mongolia is seriously injured. The GOM should acknowledge their understanding of this, but can ask for a bigger slice of the pie for future Mining IAs if they think they can do that and still attract foreign enterprise.
Someone pointed out that the GOM will be paid taxes too. The current IA is incredibly rich for the GOM. If they want other concessions to save face, maybe, but I don't think Rio will budge an inch on 34% or whatever is in place for the royalty.
This is what I mean by not giving them a thing. The integrity of those terms can't be changed and re-figured. Such an event would let the world know that IA agreements aren't worth much in Mongolia. Who's going to want to start up there, if Rio has the rug pulled out from underneath them? Any other interested industrialist would decide to stay clear of Mongolia out of fear for the same happening to them, and look for a location where the terms of business contracts are upheld.