Irrational Games as we know it closed in February, though the BioShock studio lives on in a way with a small group of survivors under Ken Levine at a new team within 2K. Once upon a time, though, there were two Irrationals. A Canberra arm of Irrational was founded in 2000, then later renamed 2K Australia. It mostly worked with Irrational and other 2K studios, on games from Freedom Force to BioShock Infinite, but most recently was behind Borderlands: The Pre-sequel. And now it’s gone too.
Parent company 2K Games have confirmed that they’re closing the studio and laying off the staff. Sounds like it was too expensive for them, and too remote.