UPDATE 10/05/2016 8.56pm: Another Xbox One backwards compatibility update has added Deus Ex: Human Revolution - Director's Cut, Faery: Legends of Avalon, Final Fight: Double Impact, Frogger 2, and Puzzlegeddon.
It's worth noting that Deus Ex: Human Revolution's original release was already backwards compatible, but now its disc-only enhanced version with tweaked boss battles and DLC can be played on Xbox One as well.
UPDATE 05/05/2016 5.10pm: Another five titles have been added to Xbox One's backwards compatibility library. They include: Dig Dug, Samurai Showdown 2, Runner2, Phantasy Star 2, and Sonic & Knuckles.
UPDATE 04/05/2016 5.47pm: Star Wars: The Force Unleashed and Star Wars: The Force Unleashed 2 have just been added to the Xbox One's backwards compatibility list. (Thanks, TrueAchievements!) May the fourth be with you!
ORIGINAL STORY 03/05/2016 11.34pm: Jet Set Radio is one of three new titles currently available on Xbox One via Xbox 360 backwards compatibility.
The other games included in today's update are MX vs. ATV Reflex and Texas Hold 'Em, a 2007 XBLA poker title by Gearbox Software before it blew up with Borderlands.
Last week's update to the backward compatibility library included Altered Beast, Comix Zone, Double Dragon: Neon, The Cave, Frogger, Galaga Legions DX, and Ghostbusters: Sanctum of Slime.