This link at the United States Patent and Trademark Office website reveals that Electronic Arts has filed trademark registrations for Dungeon Keeper. Unfortunately, the listings don't reveal anything juicy, and it may be possible that the publisher is merely refreshing the Dungeon Keeper trademark. However, with reports claiming that EA my be reviving classic IPs developed by Bullfrog Productions, a new Dungeon Keeper title may be very well be a likely candidate.
UK developer Bullfrog Productions was founded by Les Edgar and Peter Molyneaux back in 1987. The company created numerous PC games including Populous, Syndicate and Theme Park before Electronic Arts acquired the company in 1995. However the developer was eventually assimilated into the EA collective after Molyneux and other members left the company, with the last titles to bear the Bullfrog logo published in 2001 (Aquarium, Theme Park Inc.).
Overall the Dungeon Keeper series spanned three installments, a real-time strategy series for the PC where players built and managed dungeons while fending off hero characters. Electronic Arts may be reviving the Dungeon Keeper series in retaliation to Blizzard's upcoming sci-fi themed RTS, StarCraft II.