2K Games has made an official announcement stating that Borderlands 2 will receive a Season Pass. They will offer four add-ons, which "each feature several hours of gameplay and introduce new adventures, allies, enemies and environments." It will cost 2400 MSP. The add-ons will also be available individually for 800 MSP.
All four add-ons are scheduled to be available by June 2013. We’ll keep you posted on any more information revealed. Borderlands 2 hits on September 18th in North America and September 21st in Europe.