They've done this so the community manager can communicate with the community better. They need to get information out quickly, and cannot have the forum system overloaded and explode as it did last night.
This is not the first time we've seen them lock the forums in the past twenty four hours, although I do hope it is the last time.
On a brighter side of things, our comments are not locked! And we don't really subscribe to the 1984 doctrine. Newspeak here I come!