Sorry, but I have to be truthful Lord_of_Me. I went into a slight convulsion when I saw your post asking what Warcraft was.
To explain a bit better, Warcraft and Warcraft II were made by Blizzard, the company that is better known now for Starcraft. The earlier games were set in a fantasy world with a Humans vs. Orcs premise that has evolved a bit over the years. They were both groundbreaking in their day (isn't every Blizzard game in one way or another?) and were both Real-time Strategy games, essentially early versions of Starcraft. Going back to them now feels really clunky since they didn't have user interfaces figured out as well then, but they were incredible strategy games in their day.
I personally wouldn't guess Blizzard would make a First Person Shooter game. There have been many attempts by non-FPS companies to break into the genre and all of them have pretty much failed. Not to say that Blizzard couldn't do it, but...it seems to me that there is more fertile ground out there. Also, the fans that their previous games have attracted tend to be more of the non-FPS crowd anyway.
As EUOL pointed out, guessing at the nature of an entirely new project is difficult, and Blizzard North is due for a release, assuming that logic holds. A Starcraft game is highly unlikely to come out of Blizzard North, since that's a Blizzard title and they tend to keep their works separate. I also wouldn't expect another MMORPG to compete with World of Warcraft. I guess I have more to say about what I don't think they'll turn out next than what they will. If we're unlucky, it will be an expansion for Warcraft III. They like to come out with an expansion soon after a game releases. Of anything I could guess, that would be the most likely.
I suppose I ought to make a legitimate guess since I started this anyway. Let's go with a sci-fi genre (details don't matter, as Blizzard worlds aren't really very original anyway) ...can't be a RTS since that would just be Starcraft all over again...I already said not a FPS or a MMORPG...I don't think adventure games make enough money for Blizzard's tastes...um....for lack of better options, how about a Role-Playing Game?
