This is where all users are notified about the major updates that occur within Torn. Users used to have the ability to post in this forum and rate threads, however, with an update Chedburn set it so all threads are automatically locked and you are unable to rate them.
There is also the Don't Miss The Memo thread located there, where minor updates are posted in the thread by Chedburn which don't require their own thread. This thread was previously located in the General Discussion forum created by Clansdancer, however, Chedburn removed it and created a new one in the announcements forum.
Blogs are occasionally posted by staff members pertaining to various things. These blogs aren't necessarily related to updates to torn they have varied from posts by Clansdancer to posts by Chedburn for the RESPO update.
You can access all blogs written by the admins here.
Information about updates with screenshots are more often or not included in the Quarterly Newsletter sent out to those who are subscribed to this service via their in game preferences.
These Newsletters also include other information about the game, such as information on how the game is run, new developers that have joined the team etc.