Well, i agree with the point of D3 and D4. Perhaps there is somethiing coming like the "druid" as character package for D3 like the necro but i don't think they will do it though they said at one of the last blizzcons that there might be more.
The thing with the MMO is different in my opinion. First, if they would do something like that, it will be with a shitload of microtransactions as every newer blizz game is. They are already speeding up the releases of hearthstone packages like hell. I would appreciate an Diablo MMO or something like old "Hellgate London" in the Diablo Universe. That was a pretty cool game.
My opinion against the MMO thing. They said some years ago, that they won't do mmo's anymore as they don't won't to be recognized as the MMO company. They even failed pretty hard with project titan. And everybody expected titan to be the new big thing from blizzard. Anything else since then is more a DLC and Esports like way.
Just look what Blizzard has done lately:
- HotS.(selling hero packages and stuff)
- Hearthstone.(already said the massive dlc release)
- Diablo 3.(nothing new happening last the necro DLC)
- Overwatch.(at the moment more cosmetics to buy)
- The casualization of WoW.
Thats all against a new mmo release in my opinion though i would appreciate it heavily.
If we go to blizz istself, i still think the new burner to rule the company would be a new warcraft4 part. And yeah the story line went to far with wow.