I am going to concentrate on some of the areas that MMOEs have going for them and perhaps suggest how these advantages can be utilised for social good.
The first one that I think is important is the reduction of the gap between people. This can take the form of:
a) Distance. Being with someone from across the world avatar to avatar is like being in the same room, well almost...
b) Equality. A beggar on the streets of Colombia given access and the skills to use the internet could walk side by side with the Queen of England
c) Discrimination. True enough people can still have their own and sometimes extreme views in an MMOE, but there is no chance for preconceptions, discrimination or fear when two people meet for the first time
d) Freedom. An MMOE can allow you to be what you want to be, explore freedoms, unmoderated by societal, religious or family pressure, which can bring people together. A certain "anonymity" to the avatar helps people to express themselves without fear of recrimination
Now advance your thinking to a global parliament, where anyone can be a member, everyone's view is equal. Put this on a discussion table, where real global issues can be debated. You would get real views from people at the sharp end of life, tempered with those in positions of power. And neither would have fear of reprisal, creating a forum for genuine discussion. Implement a translation software option and even the barrier of language can be removed, once again bringing people with different life views together.
I don't post to explain how this will be done, just to focus on the possible end result - a global forum, where frank discussion leads to equitable solutions to social issues and people living in hardship can contribute to debates for improving their quality of life.
One way this should be done is to have a global organisation responsible for the development of MMOEs, but I'll save this for next time...