Lesnar signed a one year deal with limited appearances, which will lead to a major match at Wrestlemania 29.
During his first run, Paul Heyman was his mouthpiece, calling him the "Next Big Thing". There are currently no plans to bring Heyman in with Lesnar. The reason is that Heyman is busy with a number of ongoing projects through his "Looking For Larry" agency in New York City.
There are people within WWE (and TNA) who have reached out to Heyman in recent years, but both sides could never reach an agreement. Right now WWE is working under the assumption that Heyman will not be back.