In a new BlizzCast, production director Chris Sigaty said that StarCraft II's Galaxy Map Editor could be available toward the end of the game's beta. You won't have too much time to toy around with it, though.

"We were targeting three to five months for the beta, we're really at a three month period of time for the beta at this point," said Sigaty. "We are still targeting the first half of this year, so with that in mind, it really shortens the window of time with our major content patch coming out pretty close to the end whether it's even worth it putting out the map editor at that point."

The SC2 closed beta launched on February 17th. If the three to five month estimate is accurate, it looks like the game will hit stores this summer.