Learn from the past, look to the future.
It appears that Metal Gear Online may be an actual, viable online game this time around, unlike the last few tries, where it was, at best, a novelty to mess around in, before completely giving up on it. The development of the mode seems to be keeping all the strengths and shortcomings of previous Metal Gear Online modes in mind, meaning we have a chance at getting a Metal Gear multiplayer component which actually has a shot of being in the same ballpark of quality as the single player game modes are.
That said, the developers aren’t clinging too much to the past here, either. For instance, they confirmed that while they refer to Metal Gear Online 2 (the online mode that shipped with Metal Gear Solid 4 on the PS3) when necessary, they are basing the new game mode on Metal Gear Solid as a whole. “We have access to MGO2 when we need it. MGO3 is designed with elements of Metal Gear in mind, but not just MGO2,” they said on the official MGO twitter feed.
They were also asked about whether they plan on remaking the shuttered multiplayer mode, which saw its servers closed down recently, and they confirmed that, at least as of right now, there is no such thing in the developer pipeline: “Our concentration is fully on MGO3 only, we have no plans to rerelease MGO2 or MGO1.”
Finally, they also discussed the maps in the game. Or rather, they refused to discuss them, saying only that they will share details about them at a later date (presumably E3).
Metal Gear Solid V: The Phantom Pain launches later this year on Xbox 360, Xbox One, PS3, PS4, and PC.