I don't know. All they really did with WoW was take the existing market leader and copy it with more money and less cockstab. Doing new things isn't really their strong suit. It might be a very long time before even Blizzard can beat WoW with something.
EVE-Online-but-better.
Seriously, when the only other traditional-model MMOG that is still growing subscriptions is run by amateur-hour clownshoes inbred vikings living on a glacier-encrusted volcano...maybe their game has some sort of spark that would be huge if someone halfway professional got hold of it.
"You're really a good person, aren't you? So, there's no path for you to take here. Go home. This isn't a place for someone like you."
A better Planetside and a better Eve are both appealing pitches. Under other circumstances I'd consider both to be too risky for Blizzard, Planetside never having been THAT successful and Eve occupying what is probably a relatively limited niche. But they have to do something, and just copying WoW with Starcraft skins would be almost guaranteed to disappoint.
I'd shit myself laughing if it turned out to be some sort of lightweight social game with RMT. I can just see all the current "We didn't want that business model anyway!" subscription MMO industry refugees swallowing cyanide capsules.
"You're just a dick who quotes himself in his sig." -- Schild "Yeah, it's pretty awesome." -- Me
If Blizzard wanted to look at the most successful other MMOs and duplicate but improve Blizzard-ise them, we'll end up with their version of MapleStory. And, although some may scoff, StarCraftStory would probably leave Blizzard with enough money to jumpstart the US economy singlehandedly.
I think you could just add actual gameplay to EVE, you could keep everything else as is and end up with 4 times as many people playing. Of course, who knows if you could actually support that many more people playing at once without the server imploding under the strain.