Sources:
'Final Fantasy 7 Remake' Release Date and News Update: First Installment to Come In Early 2017
'Final Fantasy 7 Remake' release news: Game most likely to be released in 2017
Final Fantasy 7 Remake Will Be Multiple Full-Sized Games
FFVII Remake: Nomura interview translation [Famitsu 25/06/15]
Kitase said he was working on all 3 titles of the remake before releasing the first one, but earlier today Nomura said they were working on the first Disc release of the FF7 remake to push toward an early 2017 release!
Some context of the interview:
Nomura: "FFVII is special and we cannot 'surpass it' just by making it look pretty. The original version is a product of 1997, so to look at it now you can feel its age in the graphics and the game systems." He also added, "I don't think merely redoing the graphics is enough to make something you can get excited by."
Kitase: "I believe that this year will still be a year of preparations for 'Finaly Fantasy VII Remake.' I'd like to create a new kind of value for the hardware that is the PlayStation 4 for our next announcement."
Yoshinori Kitase confirmed the Final Fantasy 7 remake will be a three-part game saga. The development team reportedly used the Final Fantasy XIII series, which is composed of three games, as a model for the remake.