In 2011, they announced an upcoming Hardy Boys book which quietly disappeared when both the Nancy Drew and Hardy Boys series were cancelled in 2012. Here's the description:
"Frank and Joe's latest case involves the dangerous underside of social networking. A football friend from a nearby school contacts the Hardys when a team member goes missing! One minute he was at a massive beach party that everyone from school was invited to via MyFace; the next moment he was GONE! The MyFace parties continue, but so do the crimes: robbery, kidnapping, car theft...can murder be far behind? Is MyFace a social network of friends or a network of something far more sinister?"
That sounds like it could have been an interesting book! Too bad it never got finished.
The Nancy Drew books that got cancelled at the same time were rewritten into the two-part "cruise ship in Alaska" books, which started the Nancy Drew Diaries series. It's probably for the best that the trilogy was cut down into two. Most of the trilogy stories were two-parters that did not need to be spread out to three books.