Interview with Dustin Browder Regarding the Lurker:
GSA: Any past units from the first StarCraft to make a comeback? (*cough*Lurkers*cough)
DB: There's a chance[laughs]. We're not ashamed of putting [the Lurkers] back in. I'm sure they're pretty high on the community request list. They are pretty mighty, since they offer two things to the overall Zerg strategy: the ability to attack while cloaked and the ability to push into a tier-two building. We may have different solutions other than the Lurker, but we're still working on it.