According to Eurogamer it is. But let's be honest, Gearbox President Randy Pitchford has been dancing around the concept for a while, and Gearbox have done quite well for 2K Games since coming on board for both the original Borderlands, and saving Duke Nukem Forever (even if it was poorly received by critics).
According to the Eurogamer report
, a 'friend' of theirs close to the project has told them it's definitely due for release in 2012, and that 2K Games will be making an official announcement involving the project in the very near future. And, to be honest, Eurogamer's mates haven't steered us wrong yet, so we're inclined to believe them (and have 'friends' of our own). If the game is coming - what would you like to see in a Borderlands sequel?