Definitely not gears of war. They don't want to steal the spotlight from Gears Judgement.
I'm pretty sure they said mainline Halo games will be coming every two years so no halo 5. Maybe another Halo spinoff or remake.
Forza is certainly possible but would be quite a dull announcement. I just don't see the justification of releasing so many racing games unless they are drastically different from one another.
Fable 4 also possible. Maybe now that Peter Molyneux is gone, the studio can make a deeper game. Or at the very least get rid of that god awful menu interface of fable 3.
Personally I'm hoping for a new IP or maybe a reboot of one of their older ips. A new Perfect Dark or Kameo could be great with a talented studio behind it.
I could also see it being a big game with timed exclusive dlc, maybe fallout 4 or even Grand Theft Auto 5.
