Jim Davis passed away suddenly during production of the fourth season. The production crew had his character, Jock Ewing, go offscreen for a year while they figured out how to write out his character, then finally perish in an offscreen plane crash.
Barbara Bel Geddes' character, Miss Ellie, does not appear in the rebooted series, as the actress had passed away in 2005. She is stated to have died of a heart attack sometime between the end of the original series and the pilot of the rebooted series.
J.R. Ewing in season two of the rebooted series, in the wake of Larry Hagman's death.
Defictionalization: Audrey Landers released a compilation of all the songs she sang (as Afton Cooper) on the original series as a standalone album, Dallas Feels Like Home, in 2013.
Fan Nickname: Not fans, but the actors themselves. When they looked and saw the actors playing the "New Generation" of Ewings (Christopher, Elena, Rebecca, and John Ross) were named Jesse, Jordana, Julie and Josh, they occasionally call themselves varying versions of "The J Squad" or "The J Team"
Among other notable character actors, the producers of the 2012 series seem hellbent on featuring every supporting cast member of the FOX series 24 they can find, including Carlos Bernard (Tony Almeida) as Vicente Cano, Glenn Morshower (Aaron Pierce) as Lou Rosen, Faran Tahir (Tomas Sherek) as Frank Ashkani and Annie Wersching (Renee Walker) as Alison Jones.