In a video interview with Joystiq (to be published later today), BioWare's Dr. Greg Zeschuk cleared up some of the confusion around the DLC portal. "We'll definitely have for-pay DLC down the road too," he said, revealing that the DLC through Cerberus will be free. "It's not going to be all free DLC for Mass Effect 2 -- far from that. There'll be paid DLC packs, and there'll be stuff available through Cerberus as well."
The way Zeschuk puts it, there will be two separate types of DLC: free material that is offered through the Cerberus Network and paid DLC that can be purchased without Cerberus (through BioWare or Xbox Live Marketplace).