Gearbox Software is one of a number of developers to already take advantage of a new PC-PS3 cross-platform online play solution that's been integrated into Unreal Engine 3.
In a nutshell, Epic has licensed GameSpy online tech and squeezed it into its hugely popular UE3 technology, "enabling seamless PlayStation 3 and PC online functionality. Functionality available to Unreal Engine 3 licensees via GameSpy will include cross-platform gameplay, communication tools and competition applications."