Rumored Xbox One games in development

Halo 5
Killer Instinct
BANJO KAZOOIE 4
FORZA 5
QUANTUM BREAK
HALO: SPARTAN ASSAULT
RYSE
FABLE 4
CRACKDOWN 3
FORTNINE
DEAD RISING 3
COD: Ghosts
BF 4
Witcher 3
Dying Light
PREY 2
Homefront 2
BGE 2
Mirror's edge 2
Rainbow 6 PATRIOTS
Brother in Arms
League of legends

Capcom Next gen lineup:

Dead Rising 3 (XB1 exclusive. Capcom Vancouver)
Dragon's Dogma 2 (PS4 exclusive, DD team doing it)
Darkstalkers Reborn (Wii-U Exclusive. Funded by Nintendo, Dimps + Ono)
Marvel Vs Capcom 4 (Both. Eighting + Capcom. Also "Expandable" and also allegedly taking advantage of Microsoft's E-Sports platform tools they gave to developers)
Megaman (both consoles, PC and done by "A very good US developer who you won't expect but would be very happy to hear is doing it")
New IP from Capcom Vancouver
New IP from Ninja Theory




All rumored though. List may be fake. I think Halo 5 sounds kinda fake, 'cause that's really milking the series. But some Spartan Assault side game is probably a system seller Microsoft needs/demands.