Has Blizzard ever confirmed a project in one of their main franchises like this before? The rumors are usually flying (usually for years) but they don't actually say anything till say a Blizzcon or other major Convention with a full unveil.
I get the feeling this is not a Diablo 4, hope I'm wrong. Though the idea of an Open World Diablo game mentioned below could be interesting. I wouldn't necessarily be mad about a World of Diablo either. Whatever it will be, we all know it will have revenue generators beyond just software sales..
Also, I look forward to the great Bluesnews Diablo news thread discussions. There were some doozies leading up to Diablo 3's release on this site, and well afterwards too.