Carrier landing software has already been tested, but in manned aircraft, with pilots ready to take over at any moment. So far, these tests have been successful, but the acid test will be a UCAV actually landing on a carrier, without a human on board as a backup.
The X45A had passed tests for formation flying, and dropping a JDAM (actually the new 250 pound SDB version).
The X-45C was a well developed concept:
[The X45C] was designed to weigh 19 tons, have a 2.2 ton payload and be 39 feet long (with a 49 foot wingspan.) . . . [and] would be able to hit targets 2,300 kilometers away and be used for bombing and reconnaissance missions. Each X-45C would probably cost about $30 million[.]