Fans seem to have found evidence of special holiday content launching for GTA Online very soon. This is, once again, found in the game's code, and considering Hannukah's already started and it's not out yet, its clear this content is clearly for Christmas.
For one, there is an apparent Christmas themed Cops and Crooks mission. This is a special bonus mission for the holiday, and it seems to be located on Rockford Hills.
There will be special winter sfx as well, including gradient controlled snow, as well as more uniform, last generation style snow, and an orange red sky effect while it snows.
A new high end apartment will be introduced, and from Christmas day to January 7, it will be decorated for Christmas all around. There will also be special Christmas clothes to wear, Christmas Lights around Los Santos, two very pricey and obnoxious Christmas car mod horns (that play 'Tis the Season and Deck the Halls), a Happy Holidays roof cover, a Fireworks launcher, and some unidentified bonus items you can get just for logging in on Christmas day.