I think the cameo appearances may prove to be the most difficult to resolve... from wikipedia here is a list.
Ted Cassidy as Lurch from The Addams Family - Appeared in "The Penguin's Jest."
**** Clark - Appeared in "Shoot a Crooked Arrow."
Bill Dana as José Jiménez from The Bill Dana Show - Appeared in "The Yegg Foes in Gotham."
Sammy Davis, Jr. - Appeared in "The Clock King's Crazy Crimes."
Andy Devine as Santa Claus - Appeared in "The Duo is Slumming."
Howard Duff as Sam Stone from Felony Squad - Appeared in "The Impractical Joker."
Don Ho - Appeared in "Batman's Kow Tow."
Werner Klemperer as Colonel Klink from Hogan's Heroes - Appeared in "It's How You Play the Game."
Suzie Knickerbocker (pen name of Aileen Mehle) - Appeared in "King Tut's Coup."
Jerry Lewis - Appeared in "The Bookworm Turns."
Art Linkletter - Appeared in "Catwoman Goes to College."
Cyril Lord as the Carpet King - Appeared in "Ice Spy."
Edward G. Robinson - Appeared in "Batman's Satisfaction."
Van Williams and Bruce Lee as Green Hornet and Kato - Appeared in "The Spell of Tut."
also mentioned...
Other complications/rights issues:
Christopher D. Heer, writing at the "1966 Batman Message Board", clarified a quote by moderator Lee Kirkham, noting that there will likely be the need for complicated deals regarding cameos, since "...at least some of the cameos were done as uncredited, unpaid walk-ons – which means that Fox does NOT have home video clearances for them. Either those scenes would have to be cut or an agreement reached with the actors."[15]
Kirkham's initial quote also noted that, alongside music clearance issues, there could also be problems over some of the costumes, and the original Batmobile:
"It may surprise you, but then there are also rights issues concerning the design of the unique Batmobile design used in the show, and possibly a separate issue regarding some of the costumes as well!".[16]
I really hope it happens, but I want them complete and uncut!