According to Engadget, the Master Chief Collection will include remastered versions of Halo: Combat Evolved, Halo 2, Halo 3, and Halo 4 and will be out this year.
Halo: The Master Chief Collection aims to refresh gamers’ memories about Master Chief in advance of Halo 5: Guardians.
So no Halo 3: ODST or Halo: Reach.
No other details are not known at this time.
Most likley more info will be revealed at this year’s E3.