Not likely since those still using Big Iron today are unwilling to change due to the complexity and cost prohibitive nature of such an endeavor."If it ain't broke, don't fix it."Mainframes still have major roles in big Government, Corporations, Banking, Medical, Scientific, Engineering, and Research.While Cloud Computing is relatively new on the scene and all the rave these days, cluster computing has been around much longer in various projects and has not received anywhere near the publicity that Cloud Computing has.Smaller organizations and OSS (Open Source Software) groups have already pioneered the way for such a thing to happen.But in order for networked computers to take over Mainframes to become reality, you would need a positive ROI value which simply just isn't there.Consider the expense of hardware acquisition, training current IT staff and/or hiring new staff, getting everything and everyone to work together properly and then transitioning over to a Cluster environment.Realistically, It's not likely to happen since IBM, and others are still producing evolutionary Mainframes and the TCO for them is less than that of Distributed Server environments.