The full release notes are
here.
This update fixes some serious-but-rare bugs that a few players were encountering in specific circumstances. The next release with "free DLC" will be within the next 1-2 months, but for now we wanted to go ahead and get these fixes out the door in an official capacity even though they only affect a smallish subset of players.
Our goal is always to have the play experience be as smooth as possible for all players!
Beta Updates Cumulatively Included In This Official Release- August 29th, 2010: 1.006 Beta (Monitor Resolution Support Improved)