It seems like Borderlands: The Pre-Sequel was the best selling series farewell to thew last generation of consoles, and Borderlands 3 will be built from the ground up for Playstation 4 and Xbox One. This was revealed by 2K president Karl Slatoff during last night's financial report (where they also announced record breaking numbers for Grand Theft Auto V), where he said:
"Looking further ahead, we have robust long-term pipeline of titles in development, including ground-breaking new intellectual properties and new releases from our proven franchises. For example, we can confirm that 2K and Gearbox Software will develop an all-new Borderlands game built specifically for next-gen consoles."
Borderlands 3 is still in the very early stages of development, and it was only last week it was officially confirmed that they have begun and are looking to hire new staff for this purpose.
Thanks, Gamespot.