Cheeze ball writes "Due to the level of support provided by their forums community, Runic Games has released the Torchlight 2 release date early. Torchlight 2 will be available on 20 September 2012. The 'official' announcement is tomorrow at PAX, where the game is available for play. The forums have been very supportive of the dev team, primarily because of the team's responsiveness in posting weekly updates and the way the beta test was conducted. This support prompted Runic to inform its forum community first."
If you're curious how the game is shaping up, Eurogamer has a thorough preview from a few months ago