Changes that this is no April Fool's joke are very very low. Blizzard made several April Fool's jokes:
BurgerCraft
The Second Burning Crusade Class
That's just 2, I bet there were more.
Also: If you read the News Post there carefully, you find pranks liek this:
"For example, rather than having to sit around twiddling your thumbs, waiting in a queue to get onto your preferred server, Blizzard will be treating its fans to a fully integrated game of classic Starcraft, built right into the queuing system"