The interview goes into a range of topics such as the direction the series is headed and what sort of plot the new game will follow. Wilson revealed some details about how much work they have put into it so far, claiming that they've already been working on the game for four to five years, which is impressive given the utter silence regarding this project before the formal announcement. Wilson mentioned that long time lines like these are needed to ensure the game's quality, and considering Blizzard's brilliant track record, he is probably right.
Further discussion included a brief mention about an overhaul to Battle.net. If you are a fan at all you should check the interview out.