Is Splash Screen in Blizzard Site Revealed?

I came across news with new teaser from Blizzard with unsolved with icy look alike splash screen at the Blizzard site. What announcement could Blizzard going to give now? Could it be a new Diablo game or ice from the Frozen Throne or mineral from StarCraft. StarCraft? Isn't it too early too announce the expansion pack? However, according to WorldOfWar website they manage to crack down the mystery behind the icy wallpaper.

One of their reader found an image that shows the rune which is clearly visible in the new splash screen from Blizzard is a dead ringer for a rune seen on Arthas' sword, Frostmourne in another picture. Head to WorldOfWar for the picture.

I wish it could be WarCraft, an offline version continuation of Frozen Throne. The fight is not over Arthas :)