The video comes from PlayStation Japan and has English subtitles for you. The trailer goes over the history of the MGS series and notes that this is the “conclusion” of it all.
The cool thing is that the trailer tells the story of the close relationship between MGS and PlayStation. Every title released since MGS has been released on either PlayStation home consoles or handhelds.
MGSV : The Phantom Pain releases September 1st across all platforms, and the online component will release later on October 6th for consoles and January for PC.