You heard that right!

The first campaign and multiplayer are now completely free to play.

If you bought the base game before today, you get the first expansion Heart lf the Swarm free. If you bought HotS before today, you get the second expansion Legacy of the Void for free.

Heres Blizzard's ad announcing F2P, as well as an excellent jab at EA

I'll have to check this out then

yea I was about to read the next chapter of my textbook but I think I'm gonna have to play the HotS campaign first