The rumor based on, as quoted from movieweb,

“Hollywood big wigs confirmed actor Adam West (Batman on the TV series) will make a cameo on “The Dark Knight Rises ” set to open July 20, 2012.”

Just so you know, Adam West is a Batman actor in films and television series that screened in 1966-1968. Possible role of the West has not been revealed, although previously the actor expressed his desire to play as the father of Bruce Wayne, though the character is removed from the flashback in Batman Begins.

The Dark Knight Rises hits the theaters July 20th, 2012 and stars Christian Bale, Morgan Freeman, Gary Oldman, Tom Hardy, Anne Hathaway, Marion Cotillard, Joseph Gordon-Levitt. The film is directed by Christopher Nolan.