Arthas got a statue and it is not even Warcraft's Anniversary. If the surprise is the Diablo's statue really feels like Blizzard found out about the anniversary yesterday and then said "Oh... Anniversary... Right, I ... knew it. Here, take ... this ... chocolate! I bought it this morning to celebrate! Hurray!"
Chocolate would be more exciting than what they no doubt have in mind. Did some browsing on Bash's twitter and sounds like not much will be happening this week.