A Fortnite datamine of the recent 4.0 patch has revealed a number of new Season 4 skins and emotes. These will likely appear in the store as the selection refreshes, so be sure to keep an eye out with each new reset.
Scroll down to the see the new skins and then the emotes.
Liteshow (Uncommon) and Nitelite (Uncommon)
Chromium (Rare) and Diecast (Rare)
Abstrakt (Epic) and Trailblazer (Epic)
Royale Bomber (Epic) and Glow Stick (Rare)
Tenderizer (Rare) and Renegade Roller (Epic)
Persuader (Rare) and Glow Rider (Uncommon)
Steadfast (Uncommon) and Solid Strider (Uncommon)
Tag Bag (Epic) and True North (Epic)
Emotes (coloured rarities)