I won't throw any guesses, but I will cross out the ediotrs guess for this beign a Ghost announcement - Metzen has quite clearly stated they dropped that project and even though it saddens him and he might try and do something else with the IP ( i.e. Novas charcater) there won't be a Ghost game. So I guess we'll have to wait and see ;))

I think it is about the new expansion pack of world of warcraft.The picture reminds me of "wrath of lich king" and also,all of the websites about blizzard starts with this image.
I hope the new expansion will be launched soon.

Why would they do bring this much attention to a game we ALL already know about? Not only know about,but have known a ton about it for a while. My guess is that it's either Diablo 3 or something totally new. The runes on the splash screens match runes from Diablo 2, and the shape they're going at might form a star shape if the next two fit as the 3 have so far. Hell was frozen over in Diablo 2 so the ice could be hell breaking through. Ontop of that, if you head over to the Blizzard site and check out their job openings. There are several TOP SECRET : NEXT GEN job openings so something big is in the works. Ontop of that, there is the hidden image working itself out each day through the .CSS code. No way they would do this for a game we already knew about for so long and knew so much about it. Ontop of THAT :P, in 2002 Blizzard did this type of thing to unveil SC : Ghost and then did it in 2007 to unveil SC2, so it's something new and it's going to make a bunch of peeps go nutso! More nutso then the koreans when they heard about SC2. Ontop of that!!! The tag in the URL for the splash there is the code that spells out WWI, their invitational, when the numbers match the corresponding letter in the alphabet, example would be 23 = W since W is the 23rd letter. So far it's D O W. I believe it might be Diablo Online Worldwide _ _ _ something about it being announced worldwide. Idk, but it should be exciting!