Get out your notepads and get ready for the mainframe resurgence. Tell your friends you heard it here. I'm not talking about a UNIVAC comeback, or Burroughs Large 2.0. I'm telling you, dear readers, that now's a good time to invest in the few remaining big iron dealers: IBM, Unisys, Hitachi, and Fujitsu, baby. Why, you ask? Because mainframes solve the cloud's impending challenges.