The so called "season pass" is fast becoming a must for any AAA title planning to release several pieces of DLC. It’s a great idea for consumers as we get the content at a reduced price. The publisher also benefits from guaranteed sales of DLC and a reduction in the number of copies traded in. Borderlands 2 is the latest game to dip its toe in to the seasonable water and will charge $30 for 4 chunks of DLC.
What the 4 pieces of DLC will entail is as of yet unknown. What we do know is that Borderlands 2 features 4 player co-op that will allow you to mix and match online and offline co-op allies. The game is planned for an 18th September release so not long to go.
The information was confirmed on the Neogaf forums, but due to some dodgy imagery on the sight, here is a link to the information from Kotaku. Considered yourself warn-ed.