BlizzCast Episode 13 is a StarCraft II beta special, discussing the testing that's underway for Blizzard's real-time strategy sequel (thanks StarcraftWire.net). When asked about beta testing the map editor, Chris Sigaty volunteers an estimate of how long the beta will continue, saying they are still looking to release the first installment of the game in the first half of this year:

You haven't asked this question yet, but I'll answer it ahead of time. 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. 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.

On a related note, a new version 0.3.14048 of the StarCraft II Beta is now available.