According to one modder, it is.
[dropcap size=small]T[/dropcap]The game arrived on Tuesday with four new playable characters. But the character above is believed to be a fifth character that exists in the game’s code following an update, and will most likely be a DLC character in the future. This information comes courtesy of Se7enSins forums user TechnoJacker, who reports that the Baroness character is included in the latest beta update for the PC version on Steam, but in such a way meant to not reveal her to players. At least not yet.
[dropcap size=small]“[/dropcap]The files and data for her is included in the next Borderlands Pre-Sequel update which is available on Steam if you subscribe to the beta channel. While hidden until you purchase the DLC, it’s possible to force the game to play as her with some tinkering.”
No word from TechnoJacker on precisely what kind of tinkering is involved. There are also no other details regarding what kind of character the Baroness is, other than that her name may be Aurelia.
2K has at least announced that four DLC packs are planned for the game, which will add “more characters, challenges, and missions.” These DLC packs will be made available individually, or as part of a $30 season pass.
Borderlands: The Pre-Sequel! is available now for Playstation 3, Playstation Vita, Xbox 360, & PC