I just heard some info from someone who seems trustworthy and I wanted to share the few details I was given. Feel free to believe it or not.
-My source was told by his industry contacts that Blizzard has two unannounced games in the works "that cannot [yet] be discussed" that are scheduled to be released by year's end.
Now, speculation from my source (a fellow Gaffer who wants to protect his sources) based on what he knows about his contacts:
-He is confident that at least one of them is for Wii U, if not both.
-He believes Blizzcon 2012 was cancelled for more reasons than just to focus on SC2 and Diablo 3. If Blizzard had more titles coming out by the end of the year, why would they not show it off at their own show? Unless their hands were tied by heavy-duty NDAs...the kind Nintendo likes to issue...
-He believes Diablo III and StarCraft II are the safest guesses: Diablo III is, of course, officially confirmed to be coming to consoles, but Blizzard won't say which ones (NDA again?).
-His more "crazy-out-there" theory (again, all pieced together from hints dropped by his own sources and what he knows about them) is the MMO Project "Titan," which he believes might have a Free-to-Play model (downloadable from the Wii U eShop-equivalent) with microtransaction support and possibly NFC items at retail.
Thoughts? Comments? Jokes? Ridicule? Feel free. But this is what I was told, take it or leave it. :)
EDIT2: If you're reading this post linked from MyNintendoNews, please read this post instead of the article, which is mostly wrong.