According to F4WOnline.com, Shawn Michaels is expected to appear on WWE TV heading into SummerSlam, where he will be in Triple H's corner for his match against Brock Lesnar.
As far as Lesnar is concerned, it is believed that his current deal with WWE is set to expire after WrestleMania 29, and at this point many people in the company expect WWE to offer Lesnar a contract extension.
While this would be an expensive move for WWE, the company feels it can utilize Lesnar to sell more high profile matches beyond WrestleMania, and Lesnar could continue to help put over other WWE talents.
As for Paul Heyman, his current deal with WWE is rumored to expire at SummerSlam, however it is expected that he will continue to work with WWE alongside Brock Lesnar.