It's being said that Paul Heyman was warmly welcomed backstage in WWE on Monday night, and many people were very happy to see him again. The younger stars in WWE were especially happy to see him because Heyman knows many of them from their time in WWE developmental.
Regarding Heyman's future involvement in WWE storylines, the word going around right now is that it will indeed be a "legal/contractual dispute" storyline which mirrors the real life issues that Brock Lesnar has had with WWE management. Heyman will be Lesnar's "legal representative" on television and will continue to speak for him.
Heyman is also said to be interested in possibly working with C.M. Punk some time in the future, as the two have always been good friends. Heyman also did work for Punk's upcoming WWE DVD release.