Updated with additional details, including new developer, release window, and cross-play compatibility.
Gearbox Software wanted to bring Borderlands 2 to Vita. And now, they will. A Vita port of Borderlands 2 was just announced. Coming in 2014, the upcoming Vita version will be developed by Iron Galaxy Studios--developer of Divekick--and will be published by Sony.
In a blog post, Gearbox product manager Adam Fletcher wrote about how the company was "inundated" with messages from fans "pleading" for a PS Vita version.
No word yet if the Vita version will be compatible in any way with the PS3 version. Adam Fletcher told the PlayStation.Blog that they will have "more information later regarding" cross-play, cross-save, and DLC transfers.