During a Gamasutra live stream event held last week, the team interviewed Elder Scrolls Online Creative Director Rich Lambert. During the course of the discussion, Lambert indicated that the 'big things' coming for MMO development are those things that players are doing together and how they are working to build social ties. In addition, Lambert said that, rather than designing MMOs "big", making smaller, specifically targeted MMOs is the future for the genre.
According to Lambert, that, and the financial disincentive to build large, risky open-world online games, may mean that MMORPGs which innovate on social features could be the future of the genre.
You can check out the full stream and hear more of Lambert's thoughts at the link above.