Most likely Yoshi will make 50% Instanced Areas & 50% Open World Content but from the way things are looking, I think Yoshi is preventing certain mistakes FFXI had in the early times in regard to loot where Open World had the upper hand of rewards. So this time round, his probably going to let Instanced Areas have better loot drops than Open World areas inclusive of NMs and HNMs in both areas.

In this way it's fair to Instanced lovers and Open World lovers but the latter would only receive lower grade quality gear or loot. Same time players can embark on their adventures while meeting the community in the open world and those who want instance action can queue in town.

Main thing is to prevent/discourage botters & hackers. I am sure Yoshi would want that.