what skins are being released
The release date for the Halloween patch is public.
Last year they rereleased all seasonal outfits (witch, mad king) and added the bloody prince and executioner. All should come back (keep in mind that some outfits were not released right away).
Last years Halloween weapons are available in the gem-store right now, and are so inexpensive right now on the TP that I don’t expect a sale.
People hope for a rerelease of the year 1 gemstore weapons (Ghastly grinning shield), but chances are that there wolnt be a rerelease, ESP if there are new weapons.
Dataminers on reddit suggest that we may get 2 new costumes.
The Rainment of the Lich costume is almost certainly going to be released.
http://m.imgur.com/EAlzwLo
http://m.imgur.com/vFNGMtl
There are a couple of other possibles, but not as likely.