DC has announced plans for a summer Superman crossover event, beginning with the one-shot Superman: Doomed on May 7th, according to CBR.
Superman: Doomed #1 will be written by Scott Lobdell, Greg Pak, and Charles Soule, with art by Ken Lashley, and will depict Superman’s first major conflict with Doomsday (who famously ‘killed’ Superman in 1992) in the "New 52" era.  The story will continue in Action Comics #31, Superman/WonderWoman #8 and Superman #31.
All this will happen before DC Chief Creative Officer Geoff Johns, John Romita Jr. and Klaus Janson begin their much-publicized summer run on the core Superman title (see "Romita Moving to DC").