Rumor: A Fifth Blizzard Game In the Works

According to tumeroks.com, the 5th Blizzard game is in their early development stage. 5th you say - What was the fourth? If you’re still not clued in yet:
1. Starcraft II2. Diablo III3. New World of Warcraft expansion4. Next-Gen MMO5. A new unannounced game (New IP?)
The rumor surfaced last week when Blizzard posted 2 new job opportunities under the “unannounced” category for two software engineers. According to a blue post from Blizzard regarding the new positions:

The first time a new IP was hinted was as far back as 2006, when Paul Sams said the following to Gamespot:

Two years down the line, Paul Sams announces the Next-Gen MMO is in production but also mentioned interest in a new IP. So far, Paul Sams has been living up to his words. Although the title still remains a secret, it is official they are working on the Next-Gen MMO.
A few months ago you offered a job on the official Blizzard webpage, Considering a next gen MMO… A community manager added that its about a game that hasn’t been announced yet. Is there any new information on that or is Diablo the mentioned next gen MMO?
Rob Pardo: No, its obviously not, since it is not an MMO! We have another development team, that is…
So there is still one project?
Rob Pardo: Yea, there is still one “unknown” project…(source: OnlineWelten)Blizzard has very strong IP, but it also seems like all of it was created in the last century.
PS: First of all, that’s true that we’ve not introduced any new franchises this century. I think what it really comes down to is, we ask the teams what they want to make next.
I think the folks at our company are concerned, if they’re going to do a new franchise, that it be worthy -and that it be something that is equivalent or better than what we’ve done before, because they don’t want to do a franchise that’s not.
These are three of the best-selling franchises of all time, and very well-loved. So you’ve got a pretty high bar of trying to figure out what those franchises might be.
What I will say, though, is that the idea of a new franchise is very intriguing to employees of the company. Are we ever going to release a new one? I would absolutely say we will at some point. I just don’t know when that day will be quite yet. (source: Gamasutra)When the man says they’re bringing out a new game or whatever, I believe him. He has lived up to his word so far and I do feel they have the budget and are in need of banging out a new IP. Also consider the fact that they’ve yet to release any new franchise for this century.
Paul Sams: What I will say, though, is that the idea of a new franchise is very intriguing to employees of the company. Are we ever going to release a new one? I would absolutely say we will at some point. I just don’t know when that day will be quite yet.
So far, Blizzard has pretty much covered almost every genre of games out but a shooter. I wonder if that’s within the line of what they’re looking to develop. Feel free to share your thoughts and opinion.