Blizzard has posted patch notes for October 25th, which includes the new Halloween event and the return of Junkertown, Bastion and Torbjorn.
Here are some of the highlights from the patch notes:
Log in from now until the end of Season One to claim the free legendary Cursed Captain Reaper skin and Health Pack weapon charm.
The Wrath of the Bride event runs from October 25th – November 8th
Junkertown returns, performance issues on it have been fixed.